# Identify the Correct Number Operation

In this worksheet, students will learn about addition, multiplication, division and subtraction facts and use these facts to work out a missing number.

Key stage:  KS 2

Curriculum topic:   Verbal Reasoning

Curriculum subtopic:   Number Logic

Difficulty level:

### QUESTION 1 of 10

Hi number detective! We’ve got a new challenge that we need your help with. Are you ready?

Let’s think about this problem:

6 (18) 3

How could the two outside numbers (6 and 3), make the inside number (18)?

We can use any of the four main number operations to make our number.

These are: addition, subtraction, multiplication and division.

If we return to our problem, we can see that 6 x 3 = 18.

So the rule here is that the outside numbers multiply together to make the inside number.

For this next question, we need to work out the rule for the first set of numbers and then use that rule to work out the missing number in the next set.

Let’s look at a problem with two sets of numbers now:

3 (7) 4          6 ( __ ) 10

First, let’s work out how the numbers 3 and 4 make 7.

They add together to make 7.

We need to use the rule of adding the outside numbers for 6 and 10 to work out the missing number.

6 and 10 add together to make 16 so the missing number is 16.

Let’s try another one:

12 (7) 5          20 ( __ ) 4

First, we need to work out how the numbers 12 and 5 can make 7.

12 - 5  = 7. This means we are taking away the number on the right from the number on the left.

We need to apply this rule to the second pair of numbers giving us 20 - 4 which is 16.

Does that make sense?

It’s now your turn to put your skills to the test and be a number detective, hunting down those missing numbers!

Hey number detective! Welcome to an exciting number challenge.

Look at the number problem below:

3 (12) 4

How could the two outside numbers (3 and 4) make the inside number (12)?

Division

Addition

Multiplication

Subtraction

Ready for another one, number detective?

Look at this number problem:

6 (13) 7

How do the two outside numbers (6 and 7) make the inside number (13)?

Division

Multiplication

Addition

Subtraction

Look at the numbers below.

8 (12) 4

The number on the left adds to the number on the right to make the middle number.

The numbers below follow the same rule.

Which number would be in the middle?

5 (?) 3

8

15

2

-2

Look at the numbers below.

12 (4) 3

The number on the left (12) is divided by the number on the right (3) to make the middle number (4).

12 ÷ 3 = 4

The numbers below follow the same rule.

30 (?) 5

What number would replace the question mark?

25

35

6

150

You're halfway through this activity already, number detective. Terrific work!

In the number puzzle below, the left number subtracts the right number to get the middle number.

28 (25) 3

The numbers below follow the same rule.

17 (?) 4

What number needs to replace the question mark?

21

68

13

12

Look at the number puzzle below.

16 (20) 4

Work out how the two outside numbers (16 and 4) make the inside number (20) and then use the same rule to solve the number puzzle below.

13 (?) 3

10

16

39

4

Look at the numbers below.

21 (18) 3

Work out how the outside numbers (21 and 3) make the inside number (18) and use the same rule to work out the inside number below.

14 (?) 4

Type in the missing number as a digit below.

56

18

10

3.5

Nearly there, number detective!

Look at the two sets of numbers below.

3 (12) 4       5 (?) 8

Work out the rule for the first set of numbers and use this to work out the mystery number in the second set.

13

3

1.6

40

Only two more questions to go now!

Look at the two sets of numbers below.

18 (9) 2       20 (?) 5

Work out the rule for the first set of numbers and use this to work out the mystery number in the second set.

15

4

25

100

Congratulations, you have reached the final question, number detective!

Match the number sets below to their rules.

## Column B

7 (11) 4
Left number x right number
30 (25) 5
Left number + right number
6 (24) 4
Left number - right number
50 (10) 5
Left number ÷ right number
• Question 1

Hey number detective! Welcome to an exciting number challenge.

Look at the number problem below:

3 (12) 4

How could the two outside numbers (3 and 4) make the inside number (12)?

CORRECT ANSWER
Multiplication
EDDIE SAYS
I hope you've got your maths brain switched on, detective! We need to work out how we can make the number 12 by using 3 and 4. Let's try out all the choices: 3 + 4 = 7 so that's not right. 3 - 4 = -1 or 4 - 3 = 1 so neither of those are right. 3 x 4 = 12 gives us the correct answer! 3 ÷ 4 does not give us a whole number so isn't right. Therefore, the correct answer here is multiplication as 3 x 4 = 12. Make sure that you try all of the number operations until you find the one that works.
• Question 2

Ready for another one, number detective?

Look at this number problem:

6 (13) 7

How do the two outside numbers (6 and 7) make the inside number (13)?

CORRECT ANSWER
Addition
EDDIE SAYS
How did you get on with this one? Did you find how to make an answer of 13 with 6 and 7? You need to go through all the possible operations to see which one is right. 6 + 7 = 13, so the outside numbers here add to make the inside number. Prepare yourself for your next number pattern challenge...
• Question 3

Look at the numbers below.

8 (12) 4

The number on the left adds to the number on the right to make the middle number.

The numbers below follow the same rule.

Which number would be in the middle?

5 (?) 3

CORRECT ANSWER
8
EDDIE SAYS
Did you find this one more challenging? Don't worry, all these puzzles will get easier the more you practise. The key to it is to look very carefully at the first set of numbers to identify the rule that gives you the middle number. In this question, the rule is to add the outside numbers to make the middle number. As the next set of numbers are following the same rule, we need to add the two outside numbers (5 and 3) to make the inside number in this sum too. 5 + 3 = 8 so 8 is the inside number. This is confusing at first as we are used to the answer of a number problem going at the end, not in the middle! Remember that it will get easier the more you practise! So quickly on to the next one!
• Question 4

Look at the numbers below.

12 (4) 3

The number on the left (12) is divided by the number on the right (3) to make the middle number (4).

12 ÷ 3 = 4

The numbers below follow the same rule.

30 (?) 5

What number would replace the question mark?

CORRECT ANSWER
6
EDDIE SAYS
Remember to look carefully at the rule that is used in the first set of numbers, and then apply the same rule to the second set. Did you follow the dividing rule here to work out the middle number? We divide the left number by the right number. In the first set, this gave you 12 ÷ 3 = 4. In the second set, it gives you: 30 ÷ 5 = 6. This makes the missing number 6.
• Question 5

You're halfway through this activity already, number detective. Terrific work!

In the number puzzle below, the left number subtracts the right number to get the middle number.

28 (25) 3

The numbers below follow the same rule.

17 (?) 4

What number needs to replace the question mark?

CORRECT ANSWER
13
EDDIE SAYS
Are you getting the hang of these yet, number detective? We need to take away the right number from the left number to get the number in the middle. In the first set this is the sum: 28 - 3 = 25. So, in the second set, we get the sum: 17 - 4 = 13 This makes 13 the missing number. <---- Remember this way is left. This way is right ----> Prepare yourself for your next number puzzle challenge...
• Question 6

Look at the number puzzle below.

16 (20) 4

Work out how the two outside numbers (16 and 4) make the inside number (20) and then use the same rule to solve the number puzzle below.

13 (?) 3

CORRECT ANSWER
16
EDDIE SAYS
Now this was a challenge as you had to work out the first rule yourself! How did you get on with that? Did you notice that the number on the left of the first set of numbers (16), is added to the number on the right (4), to make the inside number (20)? We need to follow this rule with the second set of numbers and add the right number to the left number. This gives us: 13 + 3 = 16. This makes 16 the missing number. We need your excellent number puzzle skills on the next question...
• Question 7

Look at the numbers below.

21 (18) 3

Work out how the outside numbers (21 and 3) make the inside number (18) and use the same rule to work out the inside number below.

14 (?) 4

Type in the missing number as a digit below.

CORRECT ANSWER
10
EDDIE SAYS
Did you notice how the two outside numbers made the inside number here? 21 - 3 = 18. The rule here is that we subtract the number on the right (3), from the number on the left (21), to give the middle number (18). We need to follow this rule with the next set of numbers and this give us the sum: 14 - 4 = 10. Our missing number is 10. Make sure you've got your lefts and rights sorted!
• Question 8

Nearly there, number detective!

Look at the two sets of numbers below.

3 (12) 4       5 (?) 8

Work out the rule for the first set of numbers and use this to work out the mystery number in the second set.

CORRECT ANSWER
40
EDDIE SAYS
Did you work out the rule for the first set of numbers? If you tested out all the possible operations, you would have seen that addition couldn't work (3 + 4 = 7), subtraction couldn't work (3 - 4 = -1, or 4 - 3 = 1) and nor could division (3 ÷ 4 can't work.) This leaves us with multiplication: 3 x 4 = 12 The rule is that we multiply the left number by the right number to get the answer in the middle. So, we need to do this with the next set of numbers: 5 x 8 = 40. 40 is our mystery number. Are you getting the hang of this, detective?
• Question 9

Only two more questions to go now!

Look at the two sets of numbers below.

18 (9) 2       20 (?) 5

Work out the rule for the first set of numbers and use this to work out the mystery number in the second set.

CORRECT ANSWER
4
EDDIE SAYS
A trickier one - how did you get on with it? How do 18 and 2 make the number 9? If you went through all the possible operations, you will have found that the only one that works is: 18 ÷ 2 = 9. The rule is that we divide the number on the left by the number on the right, to get the number in the middle. So, to work out the next mystery number, we have to do 20 ÷ 5. This is 4, which makes 4 the mystery number. Great job, detective!
• Question 10

Congratulations, you have reached the final question, number detective!

Match the number sets below to their rules.

CORRECT ANSWER

## Column B

7 (11) 4
Left number + right number
30 (25) 5
Left number - right number
6 (24) 4
Left number x right number
50 (10) 5
Left number ÷ right number
EDDIE SAYS
How many matches did you find number detective? Let's go through them all to make sure you've got the idea. 7 (11) 4 7 + 11 = 4 30 (25) 5 30 - 5 = 25 6 (24) 4 6 x 4 = 24 50 (10) 5 50 ÷ 5 = 10 Well done for all of your number operation work today, detective! You should now feel confident when asked to identify, apply and inverse basic operations. There are further similar activities for you to try if you want to challenge yourself.
---- OR ----

Get started for free so you can track and measure your child's progress on this activity.

### What is EdPlace?

We're your National Curriculum aligned online education content provider helping each child succeed in English, maths and science from year 1 to GCSE. With an EdPlace account you’ll be able to track and measure progress, helping each child achieve their best. We build confidence and attainment by personalising each child’s learning at a level that suits them.

Get started

Try an activity or get started for free

• Tuition Partner