Interestingly, some of the addition statements can be answered by subtraction and some of the subtraction statements can be completed by addition. For example: 35 + ?? = 75 can be done by subtracting 35 from 75. An equally good method would be to add on in tens from 35 to 75.

In the same way 36 – ?? = 20 can be completed by adding on from 20 up to 36, or simply by subtracting 20 from 36. This all helps with understanding the relationship between addition and subtraction.

This set of worksheets, which because it involves both addition and subtraction is slightly harder than just dealing with one, can be found in the Year 4 addition category.

Go to Year 4 addition and subtraction questions

Once they have found the missing digits they can check if it is correct by adding the answer to the bottom line of the question. This should give the number on the top line.

This is a good way to test to see if written subtraction is understood, but should not be given to children until they have had plenty of practice with the standard method. The worksheets can be found in our Year 5 Subtraction category.

Go to Year 5 subtraction: missing digits

It is a good idea to read the subtraction number sentence out loud and discuss what kind of story could be written. Say out loud one or two before writing down a sentence. Whilst they should be kept short there is plenty of opportunity for imagination. For those children who get completely stuck there are some simple words and pictures to help them on their way.

Writing these sentences can encourage the use of the important vocabulary such as subtraction, take away and less than and put the abstract numbers and signs into a real context.

Later the number story can be read out loud and the subtraction rewritten using numbers and signs.

Go to Subtraction number sentences

The key to success here is to lay the question out in a vertical form, making sure that the decimal points line up under each other and that there are always two digits after the decimal point: the tenths (10ps) and the hundredths (1ps).

If this is done the decimal point can be placed in the answer and the question tackled like any other 3-digit subtraction.

The first 8 questions have been laid out in the correct format, but it is important that the rest of the questions are laid out in the same way, as this is not a mental arithmetic exercise, even if some could be done mentally.

Of course it is always important to check answers and the best way to do this is to add the bottom two rows, the total of which should match the top row.

Go to Written Methods of Subtracting Money

Our great subtraction activities help with this by showing clearly the step by step approach needed on screen. The first looks at subtracting two 2-digit numbers, where an adjustment will always need to be made, because the units on the second line are larger than the units on the top line.

The second looks at subtracting two 3-digit numbers where an adjustment will always be made from the hundreds to the tens.

The third looks at subtraction of money with an adjustment from the tenths to the hundredths.

By pressing return after inputting each number you are automatically taken to the next box to complete. There is a Help link which further explains this step by step approach.

All three of these activities need adjustment to take place, but ‘in real life’ this is not always the case so it would be a good idea to also practice on paper, using some of our subtraction worksheets.

There is an explanation page at the start of this set of worksheets. There are two main areas of difficulty. Watch out for the common error of jumping straight from the hundreds to the units; this makes the the number 100 less but the adjustment only 10 more, so the final calculation will be 90 less than it should be.

Another common error that children make is to say that zero subtract three is 3. This of course makes the calculation easier as there is no adjusting to do, but will result in an incorrect answer!

A rule is given, such as ‘Add 26′ and a table below the rule has to be completed.

There are two columns in the table, IN and OUT. The calculation required depends on which part of the table is missing. This can get confusing for children but is a great way to show the relationship between addition and subtraction.

The last part of the page has a table where the rule is not given. This can be worked out by looking at the row where both numbers have been given.

Go to In-Out function machines for Year 5

Most of the subtractions we ever do, we do ‘in our heads’, not on paper. Even if we use a calculator we should do a quick mental approximate answer to check that we haven’t pressed the wrong keys. But, when we subtract ‘in our heads’ we frequently just add! For example 23 – 19  = 4 I can do quite easily by counting on from 19, adding 1 to make 20, and then 3 to make 23.

It’s amazing how much can be achieved just from a good knowledge of addition and these pages help children appreciate this.

Go to our addition helping subtraction pages

Here we have some great pages for practising subtracting multiples of 10. Children who have learnt their addition of single digit facts should find these straightforward.

It is interesting to ask ourselves how we actually go about answering questions such as these in our heads. Some we just seem to know eg 40 – 30. Others require a quick mental calculation. For 60 – 30 I count up in tens from 30 to 60 in my head at an incredible speed that I hardly realise that is what I am doing. For 80 – 20 I take 2 from 8, which I know is 6, and then make the answer 10 times bigger. Or do I? I think that I might well take either of these approaches at different times. The main point is that I can answer them in less than one second each and as children gain confidence they should also be able to answer very quickly. For now, however, they are probably still counting on fingers or out loud. Do discuss with your children how they do these and how you do them.

Go to our Subtract multiples of ten resources

It is important that children recognise that subtraction questions can be phrased in several different ways. These four worksheets use the following:

9 take away 4

take 4 from 9

9 subtract 4

subtract 4 from 9

what is 4 less than 9 ?

how many less is 4 than 9 ?

With these questions children sometimes become confused as to which number they are subtracting from and this can lead to problems later with written methods, so it is worthwhile spending time on these terms.

These worksheets can be found in the Superbrains section, under Subtraction.

Go to our Subtraction questions.