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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Friday January 09 2026
01:46:28 PM | Friday January 09 2026
01:46:28 PMFlip Answers |
| 1) | 393 * 407 = | | 1) 400 * 400 - 7 * 7 = 159951 |
| 2) | 201 * 199 = | | 2) 200 * 200 - 1 * 1 = 39999 |
| 3) | 190 * 210 = | | 3) 200 * 200 - 10 * 10 = 39900 |
| 4) | 292 * 308 = | | 4) 300 * 300 - 8 * 8 = 89936 |
| 5) | 302 * 298 = | | 5) 300 * 300 - 2 * 2 = 89996 |
| 6) | 201 * 199 = | | 6) 200 * 200 - 1 * 1 = 39999 |
| 7) | 194 * 206 = | | 7) 200 * 200 - 6 * 6 = 39964 |
| 8) | 205 * 195 = | | 8) 200 * 200 - 5 * 5 = 39975 |
| 9) | 109 * 91 = | | 9) 100 * 100 - 9 * 9 = 9919 |
| 10) | 191 * 209 = | | 10) 200 * 200 - 9 * 9 = 39919 |
| 11) | 46 * 165 - 65 * 46 = | | 11) ( 165 - 65) * 46 = 4600 |
| 12) | 49 * 89 + 89 * 151 = | | 12) ( 151 + 49) * 89 = 17800 |
| 13) | 261 * 42 - 42 * 61 = | | 13) ( 261 - 61) * 42 = 8400 |
| 14) | 81 * 64 + 81 * 36 = | | 14) ( 36 + 64) * 81 = 8100 |
| 15) | 21 * 136 + 21 * 64 = | | 15) ( 136 + 64) * 21 = 4200 |
| 16) | 265 * 97 - 97 * 65 = | | 16) ( 265 - 65) * 97 = 19400 |
| 17) | 40 * 71 + 129 * 40 = | | 17) ( 129 + 71) * 40 = 8000 |
| 18) | 160 * 22 - 22 * 60 = | | 18) ( 160 - 60) * 22 = 2200 |
| 19) | 73 * 38 + 73 * 62 = | | 19) ( 38 + 62) * 73 = 7300 |
| 20) | 147 * 81 - 47 * 81 = | | 20) ( 147 - 47) * 81 = 8100 |
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Score: ______________ | |
