Multiply before you add
Today I can use the order of operations when multiplication is combined with addition or subtraction.
A Look back3 min
- 1.
6 × 7 =
- 2.
A bar has 84 squares. 39 are red. How many are blue?
- 3.
48 ÷ 6 =
B Watch me, then you4 min
Ravi has 4 stickers. He buys 3 packs with 5 stickers in each pack. How many stickers does he have now?
Multiply first: 3 × 5 = 15.
Then add the 4 stickers Ravi already had.
4 + 15 = 19, so Ravi has 19 stickers.
- 1.
2 + 4 × 6 =
C Your turn6 min
- 1.
3 + 4 × 2 =
- 2.
3 + 5 × 2 =
- 3.
3 + 5 × 4 =
- 4.
23 − 5 × 4 =
Say it out loud: Which part of each sum did you do first, and why? What changed from one row to the next?
D Spot the mistake3 min
- 1.
What does 4 + 3 × 5 really equal?
E Think deeper4 min
- 1.
Put one pair of brackets into 2 + 3 × 4 so the answer is 20. Write your equation.