What you need to know

Things to remember:

• We do our order of operation in a specific order.
• We do all the division first, then the multiplication, then the addition, and finally the subtractions.

Here, “operations” is just the mathy term that groups addition, subtraction, multiplication, and division together. The “order of operation” tells us which order we do them in. We have acronym we can use to help us remember:

Brackets
Indices
Divide
Multiply
Subtract

We will just be focusing on addition, subtraction, multiplication and division here though.

Try this question and see what you get

$$5+6\times2+4$$

If we were to just go from left to right, then we get the following answer:

$$5+6\times2+4=11\times2+4$$

$$11\times2+4=22+4$$

$$22+4=26$$

Our answer is 26! Right? Right?… Not quite. This is where we need to use BIDMAS. So, let’s see how we use BIDMAS to do these types of questions.

What is the value of $5+6\times2+4$?

Step 1: Do we have any brackets?

No. Move on.

Step 2: Do we have any indices?

No. Move on.

Step 3: Do we have any divisions?

No. Move on.

Step 4: Do we have any multiplications?

Yes, do them.

$$6\times2=12$$

$$5+6\times2+4=5+12+4$$

Step 5: Do we have any additions OR subtractions?

HINT: Once we are left with additions and subtractions, you can just do them from left to right.

$$5+12+4=21$$

So, the actual answer is 21!

$$5+6\times2+4=21$$

What is the value of $48\div4-3\times3$?

Step 1: Do we have any brackets?

No. Move on.

Step 2: Do we have any indices?

No. Move on.

Step 3: Do we have any divisions?

Yes, do them.

$$48\div4=12$$

$$48\div4-3\times3=12-3\times3$$

Step 4: Do we have any multiplications?

Yes, do them.

$$3\times3=9$$

$$12-3\times3=12-9$$

Step 5: Do we have any additions OR subtractions?

HINT: Once we are left with additions and subtractions, you can just do them from left to right

$$12-9=3$$

This finishes our question, so our final answer is:

$$48\div4-3\times3 =3$$

Example Questions

Step 1: Do we have any brackets?

No. Move on.

Step 2: Do we have any indices?

No. Move on.

Step 3: Do we have any divisions?

Yes, do them.

$$25\div5=5$$

$$6\times12+25\div5=6\times12+5$$

Step 4: Do we have any multiplications?

Yes, do them.

$$6\times12=72$$

$$6\times12+5 =72+5$$

Step 5: Do we have any additions OR subtractions?

HINT: Once we are left with additions and subtractions, you can just do them from left to right

$$72+5=77$$

$$6\times12+25\div5=77$$

Step 1: Do we have any brackets?

No. Move on.

Step 2: Do we have any indices?

No. Move on.

Step 3: Do we have any divisions?

No. move on.

Step 4: Do we have any multiplications?

Yes, do them.

$$2\times4=8$$

$$3\times7=21$$

$$12-5+2\times4 + 3\times7=12-5+8+21$$

Step 5: Do we have any additions OR subtractions?

HINT: Once we are left with additions and subtractions, you can just do them from left to right

$$12-5+8+21 =36$$

If it helps, you can do them one by one.

$$12-5+8+21 = 7 + 8 + 21 = 15 + 21 = 36$$

$$12-5+2\times4 + 3\times7 =36$$