How to find missing numbers

Look at these number frogs all a muddle in a puddle!

There are so many jumping around. How do we know if they are all here?

Let’s start by getting you all in order from smallest to the biggest. Hop to it!

Right! Here we go! One, two, three, four, five. Perfect!

When we put them in order, it’s easy to see they’re all there.

Oh no! One has gone missing.

To find out which one is missing, we need to find out where it should go in the line.

One, two, that’s the missing number, four, five.

Now we know the missing number is one more than two and one less than four.

One more than two is three and one less than four is also three.

That means our missing number here is three!

So, once we know what is one more or one less than our missing number,we can easily find our hoppy little friend.

Oh here we croak again!