Topic 4 Review

Mental Math

100

86+25

111

200

239+509

748

300

782-14

768

400

566-359=

207

500

169-48=

121

Estimating Sums and Differences

100

Round you sum to the nearest ten.

542+27=

570

200

Round the difference to the nearest ten.

281-172=

110

300

Round the sum to the nearest hundred

368+137=

500

400

Round the difference to the nearest hundred

778+95=

900

500

Round the sum to the nearest thousand.

1,346 + 827=

2,000

Adding whole numbers

100

486+875+45

1,406

200

938+1,487+8,947=

10,172

300

7,226+1,587+72,984=

81,797

400

54,236 +233 +7,856=

62,315

500

8,738+ 5,234+ 836+ 237=

15,045

Subtracting Whole Numbers

100

520-203=

317

200

7,242- 158=

7,084

300

6,797-1,298=

5,499

400

7,392-4,597=

2,795

500

5,216+2,158=

3,058

Subtracting Across Zeros

100

905-45=

861

200

800-139=

661

300

1,070-593=

477

400

8,904-3,596=

5,308

500

3,007-2,366=

641