Column Subtraction with exchange

Now your child has practiced subtraction in columns without exchange, they are ready to understand why we can exchange a group of tens to add more to the units column.

Explain that when the units digit is not large enough to take away from, they will need to borrow a ten from the tens column to make the units number larger. They must remember to cross out the tens digit they are borrowing from and write the new tens digit in its place.

Watch the clip below to practice with your child.


Column subtraction without exchange

Now your child has a secure understanding of the value of digits within each column they are ready to move to column subtraction without exchange.

This means that the number they are subtracting from has a larger number in the units column than the number they are subtracting.

e.g.      47 – 24 =       or           56 – 31 =

Explain the importance of keeping the sum and the answer in columns  as this will help to prevent mistakes when subtracting .

Watch the clip below to practice this method with your child.