Find the missing number: 3, □, 11, 15

Step by step

The question

Question: what is the missing number?

3, □, 11, 15.

1 Find the jumps

2 Find the rule

Every jump is the same: +4.

The rule is: add 4 each time.

3 Use the rule

The number before the box is 3.

3 + 4 = 7.

So the missing number is 7.

4 Check

One more jump from 7 must give 11.

7 + 4 is 11.

Yes!

It works.

Let's look back.

First: find the jumps.

Then: find the rule.

Then: use the rule.

Last: check.