MULTIPLICATION BY 9
STEP 1. Subtract the right-hand figure of the long number from 10. This gives the right-hand figure of the answer.
STEP 2. Taking the next digit from right, subtract it from 9 and add the neighbor on its right.
STEP 3. At the last step, when you are under the zero in front of the long number, subtract one from the neighbor and use that as the left-hand figure of the answer.
EXAMPLE : 8576 × 9 =?
SOLN: (08576 × 9)/77184
STEP 1. Subtract the 6 of 8576 from 10, and we have 4 of the answer.
STEP 2. Subtract the 7 from 9 (we have 2) and add the neighbor 6 ; the result is 8.
STEP 3. (9 – 5) + 7 = 11; put 1 under the line and carry over 1.
STEP 4. (9 – 8) + 5 +1(carried over) =7 ; put it down.
STEP 5 (last step). We are under the left-hand zero, so we reduce the left-hand figure of 8576 by one, and 7 is the left-hand figure of the answer.
This answer is 77184.
ANOTHER METHOD:
STEP 1. Put a zero at the right end of the number; i.e., eright 85760 for 8576.
STEP 2. Subtract the original number from that number. Like
85760 – 8576 = 77184
Here are a few questions for you.
34 × 9 = ? 2) 569 ×9= ?
1328 × 9 = ? 4) 32659 × 9 = ?
2589 × 9 = ?