Math Main Page => Exercises - Math III
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Goal: to practice how to make use of distributive property on special numbers, like (A + B) * (A - B) = A*A - B*B, A*C +B*C = (A + B ) *C, A*C - B*C = (A-B) * C
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Thursday May 14 2026
12:00:10 PM | Thursday May 14 2026
12:00:10 PMFlip Answers |
| 1) | 93 * 107 = | | 1) 100 * 100 - 7 * 7 = 9951 |
| 2) | 204 * 196 = | | 2) 200 * 200 - 4 * 4 = 39984 |
| 3) | 198 * 202 = | | 3) 200 * 200 - 2 * 2 = 39996 |
| 4) | 198 * 202 = | | 4) 200 * 200 - 2 * 2 = 39996 |
| 5) | 110 * 90 = | | 5) 100 * 100 - 10 * 10 = 9900 |
| 6) | 209 * 191 = | | 6) 200 * 200 - 9 * 9 = 39919 |
| 7) | 391 * 409 = | | 7) 400 * 400 - 9 * 9 = 159919 |
| 8) | 397 * 403 = | | 8) 400 * 400 - 3 * 3 = 159991 |
| 9) | 302 * 298 = | | 9) 300 * 300 - 2 * 2 = 89996 |
| 10) | 391 * 409 = | | 10) 400 * 400 - 9 * 9 = 159919 |
| 11) | 149 * 40 - 40 * 49 = | | 11) ( 149 - 49) * 40 = 4000 |
| 12) | 85 * 155 - 85 * 55 = | | 12) ( 155 - 55) * 85 = 8500 |
| 13) | 157 * 83 + 43 * 83 = | | 13) ( 157 + 43) * 83 = 16600 |
| 14) | 92 * 135 - 92 * 35 = | | 14) ( 135 - 35) * 92 = 9200 |
| 15) | 69 * 81 + 31 * 81 = | | 15) ( 31 + 69) * 81 = 8100 |
| 16) | 57 * 90 + 90 * 43 = | | 16) ( 57 + 43) * 90 = 9000 |
| 17) | 48 * 77 + 77 * 52 = | | 17) ( 52 + 48) * 77 = 7700 |
| 18) | 97 * 249 - 97 * 49 = | | 18) ( 249 - 49) * 97 = 19400 |
| 19) | 51 * 89 + 89 * 149 = | | 19) ( 149 + 51) * 89 = 17800 |
| 20) | 88 * 158 - 88 * 58 = | | 20) ( 158 - 58) * 88 = 8800 |
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Score: ______________ | |
