Students can use the Spectrum Math Grade 3 Answer Key Chapter 3 Lesson 3.7 Estimating Subtraction as a quick guide to resolve any of their doubts
Spectrum Math Grade 3 Chapter 3 Lesson 3.7 Estimating Subtraction Answers Key
Solve each problem by using estimation.
Question 1.
Fred had 39 dollars. He gave 23 dollars to Kim. About how much money does Fred have left?
Fred has about __________ dollars left.
Answer:
Fred has about 20 dollars left,
Explanation:
Actual total number of dollars Fred had = 39 dollars, Estimated total number of dollars Fred had = 40 dollars, Actual number of dollars he gave to Kim = 23 dollars, Estimated number of dollars he gave to Kim = 20 dollars, Estimated number of dollars left with Fred = Estimated total number of dollars Fred had – Estimated number of dollars he gave to Kim = 40 – 20 = 20 dollars.
Question 2.
There are 186 apartments in an apartment building. 92 are not rented. About how many apartments are rented?
There are about __________ rented apartments.
Answer:
There are about 100 rented apartments,
Explanation:
Actual total number of apartments in a building = 186 apartments, Estimated total number of apartments in a building = 190 apartments, Actual number of apartments not rented = 92 apartments, Estimated number of apartments not rented = 90 apartments, Estimated number of apartments rented = Estimated total number of apartments in a building – Estimated number of apartments not rented = 190 – 90 = 100.
Question 3.
Sue wants to buy a bicycle for 560 dollars. She has 430 dollars. About how much more money does she need to buy the bicycle?
Sue needs about __________ more dollars to buy the bicycle.
Answer:
Sue needs about 200 more dollars to buy the bicycle,
Explanation:
Actual cost of the bicycle = 560 dollars, Estimated cost of the bicycle = 600 dollars, Actual number of dollars Sue has = 430 dollars, Estimated number of dollars Sue has = 400 dollars, Estimated number of more dollars Sue needs to buy the bicycle = Estimated cost of the bicycle – Estimated number of dollars Sue has = 600 – 400 = 200 dollars.
Question 4.
At the theater, 98 adult tickets were sold. if 210 tickets were sold, about how many children’s tickets were sold?
About ___________ children’s tickets were sold.
Answer:
About 100 children’s tickets were sold,
Explanation:
Actual total number of tickets sold = 210 tickets, Estimated total number of tickets sold = 200 tickets, Actual number of adult tickets sold = 98 tickets, Estimated number of adult tickets sold = 100 tickets, Estimated number of children’s tickets sold = Estimated total number of tickets sold – Estimated number of adult tickets sold = 200 – 100 = 100 tickets.
Question 5.
Kelly bought a roll of cloth I 97 ¡riches long. She cut 85 inches off the roll to use in a project. About how
many inches did she have left on the roll? Round to the nearest ten.
Kelly had about __________ inches left on the roll.
Answer:
Kelly had about 110 inches left on the roll,
Explanation:
Actual length of the cloth in the roll = 197 inches, Estimated length of the cloth in the roll= 200 inches, Actual length of the roll cut = 85 inches, Estimated length of the roll cut = 90 inches, Estimated cloth left on the roll = Estimated length of the cloth in the roll – Estimated length of the roll cut = 200 – 90 = 110 inches.