There are several things to look out for when subtracting, including:
a. where each of the three digits on the bottom line are smaller than the 3 digits above them e.g.
This is the easiest type of question as there is no ‘borrowing’ or ‘adjusting.
b. Where the units are larger on the bottom line e.g.
Here an adjustment of ten has to be made from the tens column to the units column to carry out the subtraction.
c. Where the tens are larger on the bottom line e.g.
here an adjustment from the hundreds to the tens has to be made.
d. Where an adjustment from the tens has to be made, but there are no tens and the adjustment has to be made from the hundreds. e.g.
This is the hardest and one which many children will make a mistake.
For further details of these go to our Four Rules/Subtraction pages.
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