© 2007 M. Tallman

A Mental Math Strategy

© 2007 M. Tallman

96 + 268+ 4

- 4

100 264+ = 364Step 1: 96 is close to 100; 100 is a much easier number to work with.

Step 2: Add 4 to 96 to make it 100.

Step 3: Subtract 4 from the other addend, 268.

Step 4: Add 100 and 264 mentally.

© 2007 M. Tallman

134 + 494- 6 +

6128 500+ = 628

Step 1: 494 is close to 500; 500 is a much easier number to work with.

Step 2: Add 6 to 494 to make it 500.

Step 3: Subtract 6 from the other addend, 134.

Step 4: Add 128 and 500 mentally.

© 2007 M. Tallman

185 + 117+

15- 15

200 102+ = 302Step 1: 185 is close to 200; 200 is a much easier number to work with.

Step 2: Add 15 to 185 to make it 200.

Step 3: Subtract 15 from the other addend, 117.

Step 4: Add 200 and 102 mentally.

© 2007 M. Tallman

456 + 130- 6 +

6450 136+ = 586

Step 1: 456 is close to 450; 450 is an easier number to work with.

Step 2: Subtract 6 to 456 to make it 450.

Step 3: Add 6 to the other addend, 130.

Step 4: Add 450 and 136 mentally.

© 2007 M. Tallman

141 + 708+

8- 8

149 700+ = 849Step 1: 708 is close to 700; 700 is a much easier number to work with.

Step 2: Subtract 8 from 708 to make it 700.

Step 3: Add 8 to the other addend, 141.

Step 4: Add 141 and 700 mentally.

© 2007 M. Tallman

A Mental Math Strategy

© 2007 M. Tallman

131

400

+ 864

131+

5316053

1+591

859

1+599

599

© 2007 M. Tallman

457

300

+ 673

457+757

7075

7+827

682

7+833

833