New
New
Year 1

Use knowledge of addition and subtraction facts within 10 to add and subtract within 20

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

New
New
Year 1

Use knowledge of addition and subtraction facts within 10 to add and subtract within 20

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

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Lesson details

Key learning points

  1. Addition facts within ten can be applied to addition within 20
  2. Subtraction facts within ten can be applied to subtraction within 20
  3. If 3 + 2 is equal to 5 then 13 + 2 is equal to 15
  4. If 5 - 2 is equal to 3 then 15 - 2 is equal to 13

Common misconception

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

Make comparisons between addition and subtraction within 10 and within 20, looking for patterns. Make sure children notice that the ones digit stays the same when we add and subtract numbers with the same ones digits such as 5 - 2 and 15 - 2

Keywords

  • Addition - To find the total, or sum, by combining two or more parts (addends), or to increase an amount by adding another.

  • Subtraction - To partition one part from another (the subtrahend from the difference), or to decrease an amount by taking an amount away.

  • Plus - A synonym for add, represented by the symbol +

  • Minus - A synonym for add, represented by the symbol -

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).

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6 Questions

Q1.
Complete the sentence: 2 plus 7 is equal to 9, so 12 plus 7 is equal to
Correct Answer: 19, nineteen
Q2.
Complete the sentence: 8 minus 3 is equal to 5, so 18 minus 3 is equal to
Correct Answer: 15, fifteen
Q3.
First, Izzy collected 13 stones and then she found 5 more. How many stones does she have now? stones
Correct Answer: 18, eighteen
Q4.
First, Izzy had 19 stickers and then she gave Sofia 7 stickers. How many stickers does Izzy have now? stickers
Correct Answer: 12, twelve
Q5.
Tick the correct examples.
2 > 5
Correct answer: 2 < 5
Correct answer: 5 > 3
5 < 3
Q6.
Which symbol should go between 7 and 9 to show that 9 is greater than 7? 7 ___ 9
>
Correct answer: <
=

6 Questions

Q1.
Which symbol goes in between the equations to make this correct?
An image in a quiz
>
Correct answer: <
Q2.
Which symbol goes in between the equations to make this correct?
An image in a quiz
>
Correct answer: <
Q3.
Which symbol goes in between the equations to make this correct?
An image in a quiz
>
Correct answer: <
Q4.
Which equation matches this problem? Laura and Jacob have 18 pencils. They hand out some and have 5 left. How many did they hand out?
18 + 5 = ?
Correct answer: 18 − 5 = ?
? = 5 + 18
Q5.
Use addition or subtraction to solve this problem. Laura and Jacob have 17 pens. 6 pens are red and the rest are green. How many are green?
Correct Answer: 11, eleven
Q6.
Use addition or subtraction to solve this problem. Laura has 12 books and Jacob have 8 books. How many books do they have together?
Correct Answer: 20, twenty