Hi number detective! We’ve got a 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 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?
Top tip: work your way through the four main number operations until you are able to reach the number inside the brackets.
It’s now your turn to put your skills to the test and be a number detective, hunting down those missing numbers!