| Sunday, May 20, 2007 |
| Squaring a 2-digit number ending in 3 |
1. Take a 2-digit number ending in 3.
2. The last digit will be _ _ _ 9.
3. Multiply the first digit by 6: the 2nd number will be the next to the last digit: _ _ X 9.
4. Square the first digit and add the number carried from the previous step: X X _ _.
Example:
1. If the number is 43, the last digit is _ _ _ 9.
2. 6 × 4 = 24 (six times the first digit): _ _ 4 9.
4 × 4 = 16 (square the first digit), 16 + 2 = 18 (add carry): 1 8 4 9.
3. So 43 × 43 = 1849.
See the pattern?
1. For 83 × 83, the last digit is _ _ _ 9.
2. 6 × 8 = 48 (six times the first digit): _ _ 8 9.
3. 8 × 8 = 64 (square the first digit), 64 + 4 = 68 (add carry): 6 8 8 9.
4. So 83 × 83 = 6889. |
posted by marhadi @ 6:10 AM  |
|
|
|
|
| About Me |
|
![]()
Name: marhadi
Home: Bekasi, Jawa Barat, Indonesia
About Me:
See my complete profile
|
| Previous Post |
|
| Archives |
|
| Artikel |
jika kamu memiliki blog atau website dapatkan ribuan dollar perbulan dari internet dengan bergabung di google adsense, semuanya gratis
|
| Links |
|
|
| Powered by |
|
|