Estimating
Find the Sum
Find the Difference
Word Problems
Vocabulary
100

Estimate the sum by rounding to the nearest hundred. 

178 + 221 =

200 + 200 = 400

100

641 + 354 = 

995

100

678 - 451 = 

227

100

Johnny walked 127 feet on Monday. Then he walked 72 more feet on Tuesday. Lastly, he walked 341 feet on Wednesday. How far did Johnny walk over all three days?

540 feet

100

What is a Sum?

The answer to an addition problem.

200

Estimate the sum by rounding to the nearest ten.

65 + 113 = 

70 + 110 = 180

200

369 + 428 =

797

200

640 - 212 = 

428

200

Mrs. Yeniffer had 537 eggs. She sold 292 eggs to a bakery. How many eggs did Yeniffer have left?

245 eggs

200

What is a difference?

The answer to a subtraction problem.

300

Estimate the sum by rounding to the nearest ten. 

684 + 159 = 

680 + 160 = 840 

300

83 + 595 = 

678

300

748 - 469 = 

279

300

Brandon spent $157 on a video game. He now has $129 in his bank account. How much money did he have to start with?

$286

300

What is an Estimate?

A number that is close to the exact number.

400

Estimate the difference by rounding to the nearest ten. 

367 - 145 = 

370 - 150 = 220

400

146 + 579 = 

725

400

905 - 147 = 

758

400

Janelle and Jarred bought 431 cards. They gave 105 cards to their friend. Then they bought 237 more cards. How many cards do they have now?

563 cards

400
An operation that tells the difference when some of all are taken away.

Subtraction

500

Estimate the difference by rounding to the nearest ten. 

713 - 469 = 

710 - 470 = 240

500

679 + 227 = 

906

500

812 - 317 = 

495

500

Ms. Whelan's sniffling students use 188 tissues on Monday, 356 tissues on Tuesday, and 275 tissues on Wednesday. Ms. Whelan had 1,000 tissues at the beginning of the week. How many tissues are left?

188 + 356 + 275 = 819

1,000 - 819 = 181

500

Two operations that undo each other, such as addition and subtraction.

Inverse Operations

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