#### Solved Examples and Worksheet for Application of Estimating Sums and Differences

Q1Jake deposited $812 in his account. Two days later, he deposited$582. Estimate the final amount in his account. Round it to the nearest hundred.
A. $1,500 B.$1,400
C. $1,200 D.$1,300

Step: 1
Round down 812 to the nearest hundred = 800
Step: 2
Round up 582 to the nearest hundred = 600
Step: 3
800 + 600 = 1,400
Step: 4
So, the amount in Jake's account is about $1,400. Correct Answer is :$1,400
Q2Maura gave $472 to Rachel and$318 to John. Estimate the total amount that Maura gave to both Rachel and John.
A. $950 B.$800
C. $900 D.$700

Step: 1
Round up 472 to the nearest hundred, 500.
Step: 2
Round down 318 to the nearest hundred, 300.
Step: 3
500 + 300 = 800
Step: 4
So, Maura gave about $800. Correct Answer is :$800
Q3Arthur deposited $423 in his bank account last month and he deposited$978 this month. Estimate the total amount that Arthur deposited.

A. $1,500 B.$1,200
C. $1,300 D.$1,400

Step: 1
Round down 423 to the nearest hundred = 400
Step: 2
Round up 978 to the nearest hundred = 1000
Step: 3
400 + 1000 = 1,400
Step: 4
So, the amount in Arthur's account is about $1,400. Correct Answer is :$1,400
Q4John traveled 202 miles on Tuesday and 303 miles the next day. Estimate the total distance that John traveled.

A. 600 miles
B. 450 miles
C. 500 miles
D. 400 miles

Step: 1
Round down 202 to the nearest hundred = 200
Step: 2
Round down 303 to the nearest hundred = 300
Step: 3
200 + 300 = 500
Step: 4
So, the total distance traveled by John is about 500 miles.
Correct Answer is :   500 miles
Q5289 elementary school students and 120 middle school students wrote letters for a time capsule. Estimate the total number of letters written.
A. 500
B. 300
C. 400
D. 440

Step: 1
Round up 289 to the nearest hundred = 300
Step: 2
Round down 120 to the nearest hundred = 100
Step: 3
300 + 100 = 400
Step: 4
So, the estimated number of letters written are about 400.
Q6Jake earns $8,265 and saves$3,325 every month. Estimate the amount of money he spends every month to the nearest hundred.
A. $5,000 B.$6,000
C. $4,000 D.$5,300

Step: 1
The amount of money Jake spends every month = Jake′s earnings - Jake′s savings.
Step: 2
= 8,265 - 3,325
[Substitute.]
Step: 3
= 8300 - 3300
[Round to the nearest hundred.]
Step: 4
= 5000
[Subtract.]
Step: 5
Therefore, Jake spends about $5,000 every month. Correct Answer is :$5,000
Q7Marv has collected $870 for a relief fund. If he wants to collect$1,000, then estimate the amount he still needs to collect.

A. $70 B.$100
C. $200 D.$300

Step: 1
Marv wants to collect $1,000. Step: 2$870 rounded to the nearest hundred is $900. [Marv has collected$870 for a relief fund.]
Step: 3
So, the estimated amount he still needs to collect = $1,000 -$900 = $100. Correct Answer is :$100
Q8Eric wants to go to his Aunt's house which is 1,000 mi away from his house. Estimate the distance Eric has to travel, if he already has traveled 560 mi.
A. 400 km
B. 300 km
C. 500 km
D. 700 km

Step: 1
Aunt's house is 1,000 mi away from Eric's house.
Step: 2
Step: 3
Round up 560 mi. to 600 mi.
[Round up 560 to the nearest 100.]
Step: 4
So, the distance he has to travel = 1,000 - 600 = 400 mi.
Correct Answer is :   400 km
Q9George deposited $8,996 in a bank. He withdrew$5,524. By estimating the amounts of money he deposited and withdrew, to the nearest thousand, find how much he will have left in the bank?
A. $3,000 B.$2,000
C. $4,000 Step: 1 8,996 rounded to the nearest thousand is 9000. 5,524 rounded to the nearest thousand is 6,000. Step: 2 The amount of money left in the bank = the amount of money George deposited - the amount of money he withdrew. Step: 3 = 9000 - 6000 [Substitute the rounded values.] Step: 4 = 3000 [Subtract.] Step: 5 So, George has about$3,000 left in the bank.
Correct Answer is :   $4,000 Q10Justin bought a shirt for$12 and a pair of trousers for $26. Estimate the total amount of money he spent. Round to the nearest ten. A.$40
B. $30 C.$300
D. $20 Step: 1 Round down 12 to the nearest ten = 10 Step: 2 Round up 26 to the nearest ten = 30 Step: 3 10 + 30 = 40 [Add the rounded values.] Step: 4 So, the amount of money Justin spent is about$40.
Correct Answer is :   $40 Q11Paula had$93. He gave $37 to Rachel. Estimate the amount left with him. Round to the nearest ten. A.$130
B. $40 C.$50
D. $60 Step: 1 Round down 93 to the nearest ten, 90. Step: 2 Round up 37 to the nearest ten, 40. Step: 3 90 - 40 = 50 [Subtract the rounded values.] Step: 4 So, Paula left with$50.
Correct Answer is :   $50 Q12In a school, there are 346 girls and 254 boys. About how many students are there in the school? A. 500 B. 600 C. 700 Step: 1 Number of girls in the school = 346. Step: 2 346 rounded to the nearest ten is 350. Step: 3 Number of boys in the school = 254. Step: 4 254 rounded to the nearest ten is 250. Step: 5 Total number of students = 350 + 250 [Substitute the rounded values.] Step: 6 = 600 [Add.] Step: 7 Therefore, about 600 students are there in the school. Correct Answer is : 600 Q13Jim's father gifted him$205 on his birthday. He spent $181 for shopping. Estimate the amount left with him. [Round to the nearest ten.] A.$50
B. $30 C.$20

Step: 1
Money with Jim = $205. Step: 2 205 rounded to the nearest ten is 210. Step: 3 Money he spent =$181.
Step: 4
181 rounded to the nearest ten is 180.
Step: 5
Money left with Jim = 210 - 180 = 30.
[Substitute the rounded values.]
Step: 6
So, the amount left with Jim is about $30. Correct Answer is :$30
Q14Lucas has 192 chocolates. He distributed 132 of them. Estimate the number of chocolates he has now.

A. 300
B. 200
C. 100

Step: 1
Number of chocolates that Lucas has = 192
Step: 2
Round 192 up to 200.
Step: 3
Number of chocolates he distributed = 132
Step: 4
Round 132 down to 100.
Step: 5
Number of chocolates he has now = 200 - 100 = 100
Step: 6
So, the estimated number of chocolates that Lucas has now is 100.
Q15There are 357 tickets to be sold for a fundraiser. Bill sold 226 of them. Rounding to the nearest ten, estimate the number of tickets yet to be sold.
A. 130
B. 110
C. 120

Step: 1
Number of tickets yet to be sold = Total number of tickets - Number of tickets sold by Bill
Step: 2
= 357 - 226
[Substitute.]
Step: 3
= 360 - 230
[Round the values to the nearest ten.]
Step: 4
= 130
[Subtract.]
Step: 5
So, the number of tickets left to be sold rounded to the nearest ten is 130.