Use knowledge of addition facts within 10 to add within 20

I can use knowledge of addition facts within 10 to add within 20

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Year 1

Use knowledge of addition facts within 10 to add within 20

I can use knowledge of addition facts within 10 to add within 20

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Lesson details

Key learning points

Addition facts within ten can be applied to addition within 20, e.g. if 3 + 2 is equal to 5 then 13 + 2 is equal to 15
A number line can be used to show the link between addition of one-digit numbers and teen numbers

Common misconception

Children may rely on counting strategies instead of using known facts to add larger numbers.

Make comparisons between addition within 10 and within 20, looking for patterns. Make sure children notice that the ones digit stays the same when we add numbers with the same ones digits such as 3 + 2 and 13 + 2.

Keywords

Addition - Bringing two or more numbers or things together to make a new total.
Add - Bringing two or more numbers or things together to make a new total.
Plus - A synonym for add, represented by the symbol +

Use number lines to show addition within 10 and within 20, drawing out the similarities. Make sure children notice that the ones digit stays the same when we add numbers with the same ones digits.

Teacher tip

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).