Ex. 123 X 13 = ?
Procedure :
1. 3 X 3 = 9
2. 3 X 2 + 3 = 9
3. 3 X 1 + 2 = 5
4. Write in the reverse order starting with the first digit of the number to be multiplied. ( Here 1)
i.e., 123 X 13 = 1 5 9 9
Ex. 5283 X 19 = ?
1. 9 X 3 = 27
2. 9 X 8 = 72 + 2 + 3 = 77
3. 9 X 2 = 18 + 8 + 7 = 33
4. 9 X 5 = 45 + 3 + 2 = 50
5. Start with the right side(7) and write down in reverse order.
i.e., 5283 X 19 = 5 |45+2 | 18+8 | 72+3 | 27
= 5 | 47 | 26 | 75 | 27
= 10 0 3 7 7
Now you can do it directly if you got the method clear.
Ex. 5283 X 16 = 5 | 32 | 20 | 51 | 18
= 8 4 5 2 8
Practice a lot to get it mastered. Try with small numbers and then increase it along with your potential.
