Whilst in year 1 and 2 the expectation is that children will know which pairs of numbers will make 10, by year 3 they are expected to be able to work out quickly pairs of numbers that make 100.
Look at: 47 + ? = 100.
It has never been made clear exactly what is meant by knowing these facts: certainly I would suggest that a quick mental sum should be sufficient rather than actually knowing that 47 needs another 53 to make 100. In other words what needs to be known is:
1. pairs that make 10
2. pairs of whole tens that make 100.
So a child could quickly add the 3 to make the next whole ten (50) and then 50 to make 100.
This maths worksheets is about this skill in completing number sentences. In each case the missing number must make the sentence correct by equalling 100.
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I REALY LOVE MATHS BUT SOMETIMES IT GETS TRICKY
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