Number (4 ops and mixed)

Hong Kong

Stage 2

Lesson

When we all agree to solve problems the same way, like we do with the order of operations, it means we can be sure problems are solved as intended. We have seen how to work with multiplication, division, addition and subtraction, to make sure we solve them in the correct order.

Sometimes, brackets are included in a problem, and when they are, we need to be sure they are given the star treatment. They help us 'group' parts of our problem, and because of that, they are solved first. Then, we follow the usual order of operations.

In this video, we solve some expressions that have brackets, as well as other operators. Then we look at two problems, that are almost identical. The thing is, one has a set of brackets included! Do we get the same answer for both problems? You'll have to watch the video to find out.

Careful!

Brackets are solved first, but if we have more than one operator *inside* our brackets, then we still need to follow the order of operations. In the case of ($3+5\times2$3+5×2), we would solve $5\times2$5×2 first, and then add $3$3.

Evaluate $12\times\left(5+6\right)-35$12×(5+6)−35

Evaluate $49-\left(37+\left(15\div3\right)\right)$49−(37+(15÷3))

Evaluate $\left(\left(36-\left(10+10\right)\right)\div2\right)+14\times6$((36−(10+10))÷2)+14×6