Step by step
The question
Question: work out (1.5 × 10³) × (2 × 10⁶).
(1.5 × 103) × (2 × 106)
1 Group the parts
Times can go in any order.
So we put the numbers together, and the powers of 10 together.
= 1.5 × 2 × 103 × 106
2 Work out each part
1.5 times 2 is 3.
1.5 × 2 = 3
We write 3 for the numbers.
= 3 × 103 × 106
The rule: same base, times, add the powers.
3 plus 6 is 9.
103 × 106 = 103 + 6 = 109
So the answer is 3 × 10⁹.
= 3 × 109
3 Check
Let's check the answer is in scientific notation.
3 is from 1 to under 10, and it is times a power of 10.
Yes!
3 is from 1 to under 10, times 109
Let's look back.
First: group the parts.
Then: work out each part.
Last: check.
Answer
= 3 × 109