1. © 2007 M. Tallman A Mental Math Strategy

2. © 2007 M. Tallman 94 - 22 + 6 + 6 100 28 - = 72 Step 1: 94 is close to 100; 100 is a much easier number to work with. Step 2: Add 6 to 94 to make it 100. Step 3: You must also add 6 to 22, which will give you 28. Step 4: Subtract 28 from 100, mentally.

3. 405 - 97 - 5 - 5 400 92 - = 308 Step 1: 405 is close to 400; 400 is a much easier number to work with. Step 2: Subtract 5 from 405 to make it 400. Step 3: You must also subtract 5 from 97, which will leave you 92. Step 4: Subtract 92 from 400, mentally.

4. 354 - 99 + 1 + 1 355 100 - = 255 Step 1: 99 is close to 100; 100 is an easier number to work with. Step 2: Add 1 to 99 to make it 100. Step 3: You must also add 1 to 354, which will give you 355. Step 4: Subtract 100 from 355, mentally.

5. 570 - 285 + 15 + 15 585 300 - = 285 Step 1: 285 is close to 300; 300 is a much easier number to work with. Step 2: Add 15 to 285 to make 300. Step 3: You must also add 15 to 570, which will give you 585. Step 4: Subtract 300 from 585, mentally.

6. 512 - 378 - 12 - 12 500 366 - = 134 Step 1: 512 is close to 500; 500 is a much easier number to work with. Step 2: Subtract 12 from 512 to make it 500. Step 3: You must also subtract 12 from 378, which will leave you 366. Step 4: Subtract 366 from 500, mentally.

7. A Mental Math Strategy

8. © 2007 M. Tallman 567 300 - 253 567 - 267 50 267 - 217 2 217 - 215

9. © 2007 M. Tallman 735 200 - 742 735 - 535 40 535 - 495 7 495 - 488