Here is part of a number line. Write the correct number in the box.
The first number we’re given at the start of the number line is 70. And we’re also given number 90 at the end of our number line. There are four divisions between 70 and 90. To help us find the missing number, we need to know which number comes after number 70. What’s the rule of the number pattern?
If we were counting in tens, the next number would be 80, then 90. We’ve reached 92 soon. So we can’t be counting in tens. Let’s try counting in fives: 70, 75, 80, 85, 90. We’re counting in fives on the number line. And the missing number is 85. 70, 75, 80, 85, 90.