| Sunday, May 20, 2007 |
| Squaring a 2-digit number beginning with 1 |
1. Take a 2-digit number beginning with 1.
2. Square the second digit (keep the carry) _ _ X
3. Multiply the second digit by 2 and add the carry (keep the carry) _ X _
4. The first digit is one (plus the carry) X _ _
Example:
1. If the number is 16, square the second digit:6 × 6 = 36 _ _ 6
2. Multiply the second digit by 2 andadd the carry: 2 × 6 + 3 = 15 _ 5 _
3. The first digit is one plus the carry:1 + 1 = 2 2 _ _
4. So 16 × 16 = 256.
See the pattern?
1. For 19 × 19, square the second digit:9 × 9 = 81 _ _ 1
2. Multiply the second digit by 2 andadd the carry: 2 × 9 + 8 = 26 _ 6 _
3. The first digit is one plus the carry:1 + 2 = 3 3 _ _
4. So 19 × 19 = 361. |
posted by marhadi @ 5:52 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 |
|
|