Powers
Start off by going to Key Skills
Introduction
I will just state a few points
any number to the power zero is one, e.g.
70=1, 30=1, 120=1, x0=1
Remember also that
7 = 71, 3= 31, etc.
Multiplying and Dividing Numbers with Indices
If I can state a couple of rules by example
73 × 72= 7(3+2)= 75
75 ÷ 72= 7(5-2) = 73
To see how these rules work, consider the 'long method' in each case.
73 × 72= (7 × 7× 7) × (7× 7) =75
and75 ÷ 72= (7 × 7× 7× 7× 7) ÷ (7× 7) = 73
These rules can be generalized to more complicated problems, for example
\[ \frac{7^5 \times 7^2}{7^3} \]
\[ = \frac{7^7}{7^3} \]
\[ =7^4 \]