Students can use the Spectrum Math Grade 3 Answer Key Chapter 1 Posttest as a quick guide to resolve any of their doubts.
Spectrum Math Grade 3 Chapter 1 Posttest Answers Key
Check What You Learned
Adding and Subtracting 1 – and 2-Digit Numbers (with renaming)
Add.
Question 1.
a.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 3 and 7 which are in one’s place. Adding 3 and 7 gives the sum as 10 which can be renamed as 10 + 0. So, 0 will be placed in the one’s digit in the answer and 1 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 2 and 4 along with the carry forwarded digit 1 will give sum as 7. So, 7 should be written in ten’s place in the answer. Finally, the sum of given two numbers is 70.
b.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 7 and 2 which are in one’s place. Adding 7 and 2 gives the sum as 9. So, 9 will be placed in the one’s digit in the answer. Next, we need to add the digits in ten’s place. Adding 1 and 2 gives the sum 3. So, 3 should be written in ten’s place in the answer. So, the sum of given two numbers is 39.
c.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 8 and 3 which are in one’s place. Adding 8 and 3 gives the sum as 11 which can be renamed as 10 + 1. So, 1 will be placed in the one’s digit in the answer and 1 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 1 and 5 along with the carry forwarded digit 1 will give sum as 7. So, 7 should be written in ten’s place in the answer. Finally, the sum of given two numbers is 71.
d.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 6 and 7 which are in one’s place. Adding 6 and 7 gives the sum as 13 which can be renamed as 10 + 3. So, 3 will be placed in the one’s digit in the answer and 1 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 0 and 2 along with the carry forwarded digit 1 will give sum as 3. So, 3 should be written in ten’s place in the answer. Finally, the sum of given two numbers is 33.
e.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 0 and 0 which are in one’s place. Adding 0 and 0 gives the sum as 0. So, 0 will be placed in the one’s digit in the answer. Next, we need to add the digits in ten’s place. Adding 3 and 5 gives the sum 8. So, 8 should be written in ten’s place in the answer. So, the sum of given two numbers is 80.
f.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 7 and 0 which are in one’s place. Adding 7 and 0 gives the sum as 7. So, 7 will be placed in the one’s digit in the answer. Next, we need to add the digits in ten’s place. Adding 2 and 0 gives the sum 2. So, 2 should be written in ten’s place in the answer. So, the sum of given two numbers is 27.
Question 2.
a.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 6 and 2 which are in one’s place. Adding 6 and 2 gives the sum as 8. So, 8 will be placed in the one’s digit in the answer. Next, we need to add the digits in ten’s place. Adding 8 and 1 gives the sum 9. So, 9 should be written in ten’s place in the answer. So, the sum of given two numbers is 98.
b.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 3 and 9 which are in one’s place. Adding 3 and 9 gives the sum as 12 which can be renamed as 10 + 2. So, 2 will be placed in the one’s digit in the answer and 1 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 6 and 2 along with the carry forwarded digit 1 will give sum as 9. So, 9 should be written in ten’s place in the answer. Finally, the sum of given two numbers is 92.
c.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 3 and 7 which are in one’s place. Adding 3 and 7 gives the sum as 10 which can be renamed as 10 + 0. So, 0 will be placed in the one’s digit in the answer and 1 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 1 and 3 along with the carry forwarded digit 1 will give sum as 5. So, 5 should be written in ten’s place in the answer. Finally, the sum of given two numbers is 50.
d.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 7 and 3 which are in one’s place. Adding 7 and 3 gives the sum as 10 which can be renamed as 10 + 0. So, 0 will be placed in the one’s digit in the answer and 1 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 4 and 2 along with the carry forwarded digit 1 will give sum as 7. So, 7 should be written in ten’s place in the answer. Finally, the sum of given two numbers is 70.
e.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 9 and 9 which are in one’s place. Adding 9 and 9 gives the sum as 18 which can be renamed as 10 + 8. So, 8 will be placed in the one’s digit in the answer and 1 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 1 and 2 along with the carry forwarded digit 1 will give sum as 4. So, 4 should be written in ten’s place in the answer. Finally, the sum of given two numbers is 48.
f.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 3 and 1 which are in one’s place. Adding 3 and 1 gives the sum as 4. So, 4 will be placed in the one’s digit in the answer. Next, we need to add the digits in ten’s place. Adding 6 and 2 gives the sum 8. So, 8 should be written in ten’s place in the answer. So, the sum of given two numbers is 84.
Question 3.
a.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 5 and 5 which are in one’s place. Adding 5 and 5 gives the sum as 10 which can be renamed as 10 + 0. So, 0 will be placed in the one’s digit in the answer and 1 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 2 and 3 along with the carry forwarded digit 1 will give sum as 6. So, 6 should be written in ten’s place in the answer. Finally, the sum of given two numbers is 60.
b.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 5 and 1 which are in one’s place. Adding 5 and 1 gives the sum as 6. So, 6 will be placed in the one’s digit in the answer. Next, we need to add the digits in ten’s place. Adding 0 and 3 gives the sum 3. So, 3 should be written in ten’s place in the answer. So, the sum of given two numbers is 36.
c.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 0 and 0 which are in one’s place. Adding 0 and 0 gives the sum as 0. So, 0 will be placed in the one’s digit in the answer. Next, we need to add the digits in ten’s place. Adding 2 and 0 gives the sum 2. So, 2 should be written in ten’s place in the answer. So, the sum of given two numbers is 20.
d.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 9 and 6 which are in one’s place. Adding 9 and 6 gives the sum as 15 which can be renamed as 10 + 5. So, 5 will be placed in the one’s digit in the answer and 1 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 4 and 2 along with the carry forwarded digit 1 will give sum as 7. So, 7 should be written in ten’s place in the answer. Finally, the sum of given two numbers is 75.
e.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 3 and 4 which are in one’s place. Adding 3 and 4 gives the sum as 7. So, 7 will be placed in the one’s digit in the answer. Next, we need to add the digits in ten’s place. Adding 3 and 4 gives the sum 7. So, 7 should be written in ten’s place in the answer. So, the sum of given two numbers is 77.
f.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 6 and 3 which are in one’s place. Adding 6 and 3 gives the sum as 9. So, 9 will be placed in the one’s digit in the answer. Next, we need to add the digits in ten’s place. Adding 4 and 5 gives the sum 9. So, 9 should be written in ten’s place in the answer. So, the sum of given two numbers is 99.
Question 4.
a.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 6 and 5 which are in one’s place. Adding 6 and 5 gives the sum as 11 which can be renamed as 10 + 1. So, 1 will be placed in the one’s digit in the answer and 1 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 8 and 0 along with the carry forwarded digit 1 will give sum as 9. So, 9 should be written in ten’s place in the answer. Finally, the sum of given two numbers is 91.
b.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 5 and 6 which are in one’s place. Adding 5 and 6 gives the sum as 11 which can be renamed as 10 + 1. So, 1 will be placed in the one’s digit in the answer and 1 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 7 and 0 along with the carry forwarded digit 1 will give sum as 8. So, 8 should be written in ten’s place in the answer. Finally, the sum of given two numbers is 81.
c.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 3, 2 and 3 which are in one’s place. Adding 3, 2 and 3 gives the sum as 8. So, 8 will be placed in the one’s digit in the answer. So, adding digits in tens place which are 1, 1 and 2 will give sum as 4. So, 4 should be written in ten’s place in the answer. Finally, the sum of given three numbers is 48.
d.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 3, 9 and 8 which are in one’s place. Adding 3, 9 and 8 gives the sum as 20 which can be renamed as 20 + 0. So, 0 will be placed in the one’s digit in the answer 2 will be carry forwarded to get added with the numbers in ten’s place. So, adding digits in tens place which are 6 and 1 along with the carry forwarded digit 2 will give sum as 9. So, 9 should be written in ten’s place in the answer. Finally, the sum of given three numbers is 90.
e.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 1, 2 and 3 which are in one’s place. Adding 1, 2 and 3 gives the sum as 6. So, 6 will be placed in the one’s digit in the answer. So, adding digits in tens place which are 1, 2 and 3 will give sum as 6. So, 6 should be written in ten’s place in the answer. Finally, the sum of given three numbers is 66.
f.
Answer:
Explanation:
First, we need to add the digits in one’s place. So, we need to add 6, 2 and 1 which are in one’s place. Adding 6, 2 and 1 gives the sum as 9. So, 9 will be placed in the one’s digit in the answer. So, adding digits in tens place which are 1, 3 and 1 will give sum as 5. So, 5 should be written in ten’s place in the answer. Finally, the sum of given three numbers is 59.
Subtract.
Question 5.
a.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. In one’s place, if we cannot subtract the subtrahend from minuend, then we should rename minuend as tens and ones. As we have 3 at one’s place in minuend, we can rename 93 as 8 tens and 13 ones. Now, subtract 5 from 13 where difference is equal to 8. So, 8 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have 8 tens. So, subtract 0 from 8 which is 8. So, the total difference is equal to 88.
b.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 3 from 6 where difference is equal to 3. So, 3 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 1 from 7 which is 6. After subtracting the given two numbers the difference is equal to 63.
c.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. In one’s place, if we cannot subtract the subtrahend from minuend, then we should rename minuend as tens and ones. As we have 2 at one’s place in minuend, we can rename 82 as 7 tens and 12 ones. Now, subtract 5 from 12 where difference is equal to 7. So, 7 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have 7 tens. So, subtract 4 from 7 which is 3. So, the total difference is equal to 37.
d.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 1 from 7 where difference is equal to 6. So, 6 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 4 from 6 which is 2. After subtracting the given two numbers the difference is equal to 26.
e.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 2 from 4 where difference is equal to 2. So, 2 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 1 from 1 which is 0. After subtracting the given two numbers the difference is equal to 2.
f.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 0 from 3 where difference is equal to 3. So, 3 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 0 from 6 which is 6. After subtracting the given two numbers the difference is equal to 63.
Question 6.
a.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. In one’s place, if we cannot subtract the subtrahend from minuend, then we should rename minuend as tens and ones. As we have 7 at one’s place in minuend, we can rename 87 as 7 tens and 17 ones. Now, subtract 9 from 17 where difference is equal to 8. So, 8 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have 7 tens. So, subtract 1 from 7 which is 6. So, the total difference is equal to 68.
b.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 3 from 8 where difference is equal to 5. So, 5 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 1 from 2 which is 1. After subtracting the given two numbers the difference is equal to 15.
c.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 2 from 5 where difference is equal to 3. So, 3 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 4 from 6 which is 2. After subtracting the given two numbers the difference is equal to 23.
d.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 5 from 7 where difference is equal to 2. So, 2 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 3 from 5 which is 2. After subtracting the given two numbers the difference is equal to 22.
e.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. In one’s place, if we cannot subtract the subtrahend from minuend, then we should rename minuend as tens and ones. As we have 3 at one’s place in minuend, we can rename 63 as 5 tens and 13 ones. Now, subtract 4 from 13 where difference is equal to 9. So, 9 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have 5 tens. So, subtract 1 from 5 which is 4. So, the total difference is equal to 49.
Question 7.
a.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 5 from 9 where difference is equal to 4. So, 4 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 2 from 3 which is 1. After subtracting the given two numbers the difference is equal to 14.
b.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 3 from 6 where difference is equal to 3. So, 3 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 2 from 4 which is 2. After subtracting the given two numbers the difference is equal to 23.
c.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 0 from 0 where difference is equal to 0. So, 0 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 2 from 8 which is 6. After subtracting the given two numbers the difference is equal to 60.
d.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. In one’s place, if we cannot subtract the subtrahend from minuend, then we should rename minuend as tens and ones. As we have 5 at one’s place in minuend, we can rename 65 as 5 tens and 15 ones. Now, subtract 9 from 15 where difference is equal to 6. So, 6 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have 5 tens. So, subtract 0 from 5 which is 5. So, the total difference is equal to 56.
e.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. In one’s place, if we cannot subtract the subtrahend from minuend, then we should rename minuend as tens and ones. As we have 2 at one’s place in minuend, we can rename 92 as 8 tens and 12 ones. Now, subtract 5 from 12 where difference is equal to 7. So, 7 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have 8 tens. So, subtract 4 from 8 which is 4. So, the total difference is equal to 47.
e.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 5 from 9 where difference is equal to 4. So, 4 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 3 from 9 which is 6. After subtracting the given two numbers the difference is equal to 64.
f.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. In one’s place, if we cannot subtract the subtrahend from minuend, then we should rename minuend as tens and ones. As we have 6 at one’s place in minuend, we can rename 86 as 7 tens and 16 ones. Now, subtract 9 from 16 where difference is equal to 7. So, 7 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have 7 tens. So, subtract 1 from 7 which is 6. So, the total difference is equal to 67.
Question 8.
a.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. In one’s place, if we cannot subtract the subtrahend from minuend, then we should rename minuend as tens and ones. As we have 3 at one’s place in minuend, we can rename 53 as 4 tens and 13 ones. Now, subtract 5 from 13 where difference is equal to 8. So, 8 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have 4 tens. So, subtract 4 from 4 which is 0. So, the total difference is equal to 8.
b.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 3 from 9 where difference is equal to 6. So, 6 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 2 from 3 which is 1. After subtracting the given two numbers the difference is equal to 16.
c.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 4 from 6 where difference is equal to 2. So, 2 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 1 from 8 which is 7. After subtracting the given two numbers the difference is equal to 72.
d.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. In one’s place, if we cannot subtract the subtrahend from minuend, then we should rename minuend as tens and ones. As we have 2 at one’s place in minuend, we can rename 92 as 8 tens and 12 ones. Now, subtract 7 from 12 where difference is equal to 5. So, 5 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have 8 tens. So, subtract 4 from 8 which is 4. So, the total difference is equal to 45.
e.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. Now, subtract 5 from 5 where difference is equal to 0. So, 0 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have to subtract 4 from 8 which is 4. After subtracting the given two numbers the difference is equal to 40.
f.
Answer:
Explanation:
While doing subtraction, first we should subtract digits in one’s place and should move to the left i.e., to the ten’s place and so on. In one’s place, if we cannot subtract the subtrahend from minuend, then we should rename minuend as tens and ones. As we have 2 at one’s place in minuend, we can rename 62 as 5 tens and 12 ones. Now, subtract 7 from 12 where difference is equal to 5. So, 5 should be written in one’s digit in the answer. Now, moving to the left that is ten’s place, we have 5 tens. So, subtract 3 from 5 which is 2. So, the total difference is equal to 25.
Solve each problem.
Question 9.
At an air show there were 32 airplanes in the sky. If 15 airplanes landed, how many were still in the sky?
There were ____ airplanes still in the sky.
Answer:
There were 17 airplanes still in the sky.
Explanation:
Subtract 15 from 32 the difference is equal to 17. There were 17 airplanes still in the sky.
Question 10.
One bag of rocks weighs 15 pounds. Another bag of rocks weighs 23 pounds. How much do both bags of rocks weigh?
Together, the bags of rocks weigh ____ pounds.
Answer:
Together, the bags of rocks weigh 38 pounds.
Explanation:
Add 15 with 23 the sum is equal to 38. Together, the bags of rocks weigh 38 pounds.
Question 11.
There were 46 people at the train station. Then, 27 people got on the train. How many people are still at the train station?
There are ____ people still at the train station.
Answer:
There are 19 people still at the train station.
Explanation:
Subtract 27 from 46 the difference is equal to 19. There are 19 people still at the train station.
Question 12.
Sally has 32 cupcakes. She gave cupcakes to 16 people. How many cupcakes does she have left?
Sally has _________ cupcakes left.
Answer:
Sally has 16 cupcakes left.
Explanation:
Subtract 16 from 32 the difference is equal to 16. So, Sally has 16 cupcakes left.
Question 13.
The car dealer had 17 model cars. Yesterday, he sold 9 of the model cars. How many model cars does he have left?
The car dealer has _________ model cars left.
Answer:
The car dealer has 8 model cars left.
Explanation:
Subtract 9 from 17 the difference is equal to 8. So,the car dealer has 8 model cars left.
Question 14.
Beatrix had invited 26 people to her party. Only 9 people could not come to the party. How many
people will be at Becitrix’s party?
There will be _________ people at Beatrix’s party.
Answer:
There will be 17 people at Beatrix’s party.
Explanation:
Subtract 9 from 26 the difference is equal to 17. So, there will be 17 people at Beatrix’s party.