Starting at 0 we can count up in 2s like this:
0 2 4 6 8 10 12 14 …
But what happens before zero?
We have the negative numbers, counting in 2s, like this:
… -14 -12 -10 -8 -6 -4 -2 0
That was counting up.
Now let’s count backwards in 2s from 14.
14 12 10 8 6 4 2 0 -2 -4 -6 -8 -10 -12 …
Example
Count backwards in 2s to work out the missing number.
8 6 4 2 0 -2 -6
What is the missing number?
Answer
Counting backwards in 2s from 0, it goes:
… 0 -2 -4 -6
So the missing number is -4
