Step by step
The question
Question: work out −2/3 × 9/10.
−23 × 910
1 Cancel first
− × + = −
Minus times plus is minus.
Before we multiply, we make the numbers smaller.
2 on top and 10 at the bottom both divide by 2.
9 on top and 3 at the bottom both divide by 3.
A top and a bottom divided by the same number: the answer stays the same.
2 and 10: ÷ 2 → 1 and 5
9 and 3: ÷ 3 → 3 and 1
So we multiply smaller numbers.
= −11 × 35
2 Multiply tops and bottoms
To multiply fractions, we do top times top, and bottom times bottom.
= −1 × 31 × 5
1 times 3 is 3.
1 times 5 is 5.
= −35
Can we make it simpler?
No number goes into both 3 and 5, except 1.
So it stays like this.
simplest ✓
So the answer is −3/5.
Let's look back.
First: cancel first.
Last: multiply tops and bottoms.
Answer
= −35