Multiplying Two Numbers Close to but less than 100
To multiply two numbers close to but less than 100, use the
following steps:
- Find the difference of each of the numbers from 100.
- Multiply these differences; write as the last two digits
of the answer on the right.
- Subtract the difference of one number from the other
original number; write as the first two digits of the
answer on the left.
Example:
98 × 97 =
- Find the differences of each number from 100: 100 - 98 =
2; 100 - 97 = 3
- Multiply these differences and write as the last two
digits of the answer. 2 × 3 = 6. Since we need to use
two digits, write 06.
- Subtract the difference of one number from the other
original number. Either combination will work. 98 - 3 =
95 or 97 - 2 = 95. Write 95 as the first two digits of
the answer.
98 × 97 = 9506. |
