Print PDF
Favorite
Email
Step 7Answers to Practice Problems
1) 441
2) 1369
3) 8649
4) 1936
5) 3844
6) 3025
7) 104.04
8) 13225
And finally, for the mental masterminds in the audience:
9) 218089
10) 613089
2) 1369
3) 8649
4) 1936
5) 3844
6) 3025
7) 104.04
8) 13225
And finally, for the mental masterminds in the audience:
9) 218089
10) 613089
| « Previous Step | Download PDFView All Steps | Next Step » |
whenever you have a number which ends in 5 you can use this. multiply the number preceding 5 with its successor. say you have 75 then multiply the preceding number 7 with it's successor 8 ( for 85 it would be 8*9), Write down the result and just write 25 to the end of this result.
So 75*75 = 7*8 = 56 now write 25 to the end of this digit = 56 25 this is the ans 5625.
The idea is to treat the number as 2 distinct numbers 1st part is the number preceding 5 and the second part is the digit 5.
so for 125 * 125 we get 12 & 5
12*13 = 156 and write 25 to the end = 156 25 ---> 15625