Step by step
The question
Question: work out 3 × √16 − 2³.
3 × √16 − 23
1 Square roots
Square roots come before times and minus.
Order: ( ) → x² √ → × ÷ → + −
√16 asks: which positive number times itself makes 16?
4 times 4 is 16.
4 × 4 = 16
So √16 is 4.
= 3 × 4 − 23
2 Powers
Powers come before times and minus.
2³ means 2 times 2 times 2.
23 = 2 × 2 × 2 = 8
That is 8.
= 3 × 4 − 8
3 Times and divide
Times comes before minus.
3 times 4 is 12.
= 12 − 8
4 Plus and minus
12 minus 8 is 4.
= 4
So the answer is 4.
Let's look back.
First: square roots.
Then: powers.
Then: times and divide.
Last: plus and minus.
Answer
= 4