In this activity, we will work out a subtraction by counting on using a number line.

Example

Work out 73 - 38 =  

We use the number line to count up from the smaller number to the larger number.  

First step: go to the next ten, i.e. 40 here (38 + 2 = 40)

Second step: count up in tens to the ten below your given number, i.e. 70 here (40 + 30 = 70)

Third step: count up to the given number, i.e. 73 here (70 + 3 = 73)

Answer is 2 + 30 + 3 = 35

So we can see that 73 - 38 = 35

Don't worry if that looks a bit tricky, we'll go through lots of questions together and hopefully, it will soon become easy!