| --- |
| source: ncert |
| topic: numbers |
| class_level: class_7 |
| chapter: ch13 |
| difficulty: beginner |
| --- |
| |
| Class 7 | Ch13: Exponents and Powers |
| a^n = a×a×...×a (n times). 2^5=32. |
| Laws (same base): a^m×a^n=a^(m+n), a^m÷a^n=a^(m-n), (a^m)^n=a^(mn). |
| Same power: a^m×b^m=(ab)^m, a^m÷b^m=(a/b)^m. |
| a^0=1 for any a≠0. |
| Standard form: number between 1 and 10 times power of 10. |
| 48000000=4.8×10^7. 0.0000035=3.5×10^(-6). |
| Examples: 2^5×2^3=2^8=256. 3^7÷3^4=3^3=27. (2^3)^2=2^6=64. 2^3×5^3=10^3=1000. |
| 2^3=8 NOT 6. a^m×a^n=a^(m+n) ADD not multiply powers. (2+3)^2≠2^2+3^2. |
