Step by step
The question
Question: work out 8 × 10⁻² divided by 4 × 10³.
8 × 10−24 × 103
1 Group the parts
We divide the numbers, and we divide the powers of 10.
= 84 × 10−2103
2 Work out each part
8 divided by 4 is 2.
8 ÷ 4 = 2
We write 2 for the numbers.
= 2 × 10−2103
The rule: same base, divide, take away the powers.
−2 minus 3 is −5.
10−2103 = 10−2 − 3 = 10−5
So the answer is 2 × 10⁻⁵.
= 2 × 10−5
3 Check
Let's check the answer is in scientific notation.
2 is from 1 to under 10, and it is times a power of 10.
Yes!
2 is from 1 to under 10, times 10−5
Let's look back.
First: group the parts.
Then: work out each part.
Last: check.
Answer
= 2 × 10−5