Go through the **Spectrum Math Grade 2 Answer Key Chapter 2 Posttest **and get the proper assistance needed during your homework.

## Spectrum Math Grade 2 Chapter 2 Posttest Answers Key

**Check What You Learned**

**Addition and Subtraction Facts through 20**

**Add.**

Answer:

7

Explanation:

Let us add 3 and 4.

Add 3 ones and 4 ones.

7 ones + 9 ones = 7 ones.

Write 6 in one’s place. Hence the answer is 7.

Answer:

10

Explanation:

Let us add 8 and 2.

Add 8 ones and 2 ones.

8 ones + 2 ones = 10 ones.

10 ones = 1 ten + 0 ones

Write 0 in one’s place and carry 1 ten to ten’s place. Hence the addtion of two given numbers is 10.

Answer:

12

Explanation:

Let us add 5 and 7.

Add 5 ones and 7 ones.

5 ones + 7 ones = 12 ones.

12 ones = 1 ten + 2 ones

Write 2 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 12.

Answer:

3

Explanation:

Let us add 2 and 1.

Add 2 ones and 1 ones.

2 ones + 1 ones = 3 ones.

Hence the addition of the two given numbers is 3.

Answer:

16

Explanation:

Let us add 9 and 7.

Add 9 ones and 7 ones.

9 ones + 7 ones = 16 ones.

16 ones = 1 ten + 6 ones

Write 6 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 16.

Answer:

18

Explanation:

Let us add 9 and 9.

Add 9 ones and 9 ones.

9 ones + 9 ones = 18 ones.

18 ones = 1 ten + 8 ones

Write 8 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 18.

Answer:

9

Explanation:

Let us add 1 and 8.

Add 1 ones and 8 ones.

1 ones + 8 ones = 9 ones.

Write 9 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 9.

Answer:

13

Explanation:

Let us add 6 and 7.

Add 6 ones and 7 ones.

6 ones + 7 ones = 13 ones.

13 ones = 1 ten + 3 ones

Write 3 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 13.

Answer:

6

Explanation:

Let us add 5 and 1.

Add 5 ones and 1 ones.

5 ones + 1 ones = 6 ones.

Write 6 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 6.

Answer:

4

Explanation:

Let us add 0 and 4.

Add 0 ones and 4 ones.

0 ones + 4 ones = 4 ones.

Write 4 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 4.

Answer:

14

Explanation:

Let us add 9 and 5.

Add 9 ones and 5 ones.

9 ones + 5 ones = 14 ones.

14 ones = 1 ten + 4 ones

Write 4 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 14.

Answer:

5

Explanation:

Let us add 3 and 2.

Add 3 ones and 2 ones.

3 ones + 2 ones = 5 ones.

Write 5 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 5.

Answer:

8

Explanation:

Let us add 6 and 2.

Add 6 ones and 2 ones.

6 ones + 2 ones = 8 ones.

Write 8 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 8.

Answer:

20

Explanation:

Let us add 12 and 8.

Add 2 ones and 8 ones.

12 ones + 8 ones = 20 ones.

20 ones = 2 ten + 0 ones

Write 0 in one’s place and carry 2 ten to ten’s place. Hence the addition of two numbers is 20.

Answer:

15

Explanation:

Let us add 8 and 7.

Add 8 ones and 7 ones.

8 ones + 7 ones = 15 ones.

15 ones = 1 ten + 5 ones

Write 5 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 15.

Answer:

17

Explanation:

Let us add 9 and 8.

Add 9 ones and 8 ones.

9 ones + 8 ones = 17 ones.

17 ones = 1 ten + 7 ones

Write 7 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 17.

Answer:

11

Explanation:

Let us add 5 and 6.

Add 5 ones and 6 ones.

5 ones + 6 ones = 11 ones.

11 ones = 1 ten + 1 ones

Write 1 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 11.

Answer:

19

Explanation:

Let us add 14 and 5.

Add 4 ones and 5 ones.

5 ones + 7 ones = 12 ones.

12 ones = 1 ten + 2 ones

Write 2 in one’s place and carry 1 ten to ten’s place. Hence the addition of two numbers is 12.

Answer:

9

Explanation:

Let us subtract 13 and 4.

Subtract 4 from 3. As 4 > 3 we cannot subtract 4 from 3. Therefore let us borrow 1 from ten’s place. Subtract 13 – 4 = 9.

Hence the answer is 9.

Answer:

6

Explanation:

Let us subtract 7 and 1.

Subtract 7 – 1 = 6. Hence the subtraction of the given two numbers is 6.

Answer:

2

Explanation:

Let us subtract 4 and 2.

Now subtract 2 from 4. 4 -2 = 2. Hence the subtraction of the given two numbers is 2.

Answer:

6

Explanation:

Let us subtract 14 and 8.

As 8 > 4 we cannot subtract 8 from 4. Therefore let us borrow 1 from ten’s place. Subtract 14 – 8 = 6. Hence the subtraction of the two given numbers is 6.

Answer:

1

Explanation:

Let us subtract 10 and 9.

Now subtract 10 – 9 = 1. Hence the subtraction of the two given numbers is 1.

Answer:

5

Explanation:

Let us subtract 5 and 0.

Now subtract 0 from 5. Hence the subtraction of the given two numbers is 5.

Answer:

10

Explanation:

Let us subtract 19 and 9.

Now subtract the numbers from one’s place. 9 – 9 = 0. Bring down the remaining 1 to down. Hence the subtraction of the given two numbers is 19 – 9 = 10.

Answer:

9

Explanation:

Let us subtract 15 and 6.

As 6 > 5 we cannot subtract 6 from 5. Therefore let us borrow 1 from ten’s place. Subtract 15 – 6 = 9. Hence the subtraction of the two given numbers is 9.

Answer:

0

Explanation:

Let us subtract 6 and 6.

6 – 6 = 0. Hence the subtraction of the two given numbers is 0.

Answer:

9

Explanation:

Let us subtract 17 and 8.

As 8 > 7 we cannot subtract 8 from 7. Therefore let us borrow 1 from ten’s place. Subtract 17 – 8 = 9. Hence the subtraction of the two given numbers is 9.

Answer:

6

Explanation:

Let us subtract 8 and 2.

8 – 2 = 6. Hence the subtraction of the two given numbers is 6.

Answer:

6

Explanation:

Let us subtract 12 and 6.

As 6 > 2 we cannot subtract 6 from 2. Therefore let us borrow 1 from ten’s place. Subtract 12 – 6 = 6. Hence the subtraction of the two given numbers is 6.

Answer:

8

Explanation:

Let us subtract 16 and 8.

As 8 > 6 we cannot subtract 8 from 6. Therefore let us borrow 1 from ten’s place. Subtract 16 – 8 = 8. Hence the subtraction of the two given numbers is 8.

Answer:

9

Explanation:

Let us subtract 18 and 9.

As 9 > 8 we cannot subtract 9 from 8. Therefore let us borrow 1 from ten’s place. Subtract 18 – 9 = 9. Hence the subtraction of the two given numbers is 9.

Answer:

16

Explanation:

Let us subtract 20 and 4.

As 4 > 0 we cannot subtract 4 from 0. Therefore let us borrow 1 from ten’s place. Subtract 10 – 4 = 6. Next bring down the 1 in ten’s place. Hence the subtraction of the two given numbers is 16.

Answer:

0

Explanation:

Let us subtract 20 and 4.

3 – 3 = 0. Hence the subtraction of the given two numbers is 0.

Answer:

3

Explanation:

Let us subtract 11 and 8.

As 8 > 1 we cannot subtract 8 from 1. Therefore let us borrow 1 from ten’s place. Subtract 11 – 8 = 3. Hence the subtraction of the two given numbers is 3.

**Solve each problem.**

Answer:

0

Explanation:

Let us subtract 9 and 9.

9 – 9 = 0. Hence the subtraction of the given two numbers is 0.

There are 15 bananas.

Joe takes 6.

How many bananas are left? ______

Answer:

There are 9 bananas left.

Explanation:

Given,

No of bananas = 15

Joe took = 6 bananas

15 – 6 = 9 bananas

The Changs have 7 apples.

Mrs. Chang buys 5 more.

How many apples do they have now? ______

Answer:

They have a total of 12 apples.

Explanation:

No of apple changs have = 7

Mrs. Changs buys 5 more

Total = 5 + 7 = 12 apples.

Therefore they have 12 apples.

The store has 12 boxes of plums.

5 boxes of plums are sold. _____

How many boxes are left? _____

Answer:

The number of boxes left is 7 plums.

Explanation:

Given,

The store has 12 boxes of plums.

5 boxes of plums are sold.

12 – 5 = 7 plums are left.

Together, Grace and her sister bought 18 bananas.

Grace bought9 bananas.

How many bananas did her sister buy? _____

Answer:

Her sister bought a total number of 9 bananas.

Explanation:

Together, Grace and her sister bought 18 bananas.

Grace bought 9 bananas.

9 + 9 = 18

Her sister bought a total number of 9 bananas.

Mrs. Lopez has 19 hats.

3 of the hats have bows.

How many hats do not have bows? _______

Answer:

There are 16 hats that do not have bows.

Explanation:

Mrs. Lopez has 19 hats.

3 of the hats have bows.

The number of hats that do not have bows is 19 – 3 = 16