Advance warning - I cannot type indices properly, so I am just doing x^2 for x squared, etc.
For those who are new entirely to this topic, an index is the "squared" bit on x^2. Ok, let's start. There are a few simple rules to indices:
What indices are
Indices are how many times you multiply the number by itself. For example, 9^3 is the same as:
9 x 9 x 9
2. A number without an index
For a number without an idex, the index is always 1. For example, 6 is really 6^1, but we write it as 6.
3. Multiply means add
Multiplying, say, 4^3 by 4^2, we just add the indices together. This works because:
4 x 4 x 4 x 4 x 4
=
4 x 4 x 4 x 4 x 4
=
4^5
4. Divide means subtract
10^8 / 10^5 = 10^3. This works in the same way as the multiplication.
5. Raising a power to another means multiply.
Raising a power to another is where you've got something like this:
(5^3)^2
Here, we MULTIPLY 3 by 2, to get 6. So our final answer is 5^6.
You can use this quick quiz to test yourself on this:
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