Starter quiz
- Complete the sentence: 2 plus 7 is equal to 9, so 12 plus 7 is equal to ______
- '19' ✓
- Complete the sentence: 8 minus 3 is equal to 5, so 18 minus 3 is equal to ______
- '15' ✓
- First, Izzy collected 13 stones and then she found 5 more. How many stones does she have now? ______ stones
- '18' ✓
- First, Izzy had 19 stickers and then she gave Sofia 7 stickers. How many stickers does Izzy have now? ______ stickers
- '12' ✓
- Tick the correct examples.
- 2 > 5
- 2 < 5 ✓
- 5 > 3 ✓
- 5 < 3
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- Which symbol should go between 7 and 9 to show that 9 is greater than 7? 7 ___ 9
- >
- < ✓
- =
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Exit quiz
Which symbol goes in between the equations to make this correct?- >
- < ✓
-
Which symbol goes in between the equations to make this correct?- >
- < ✓
-
Which symbol goes in between the equations to make this correct?- >
- < ✓
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- 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 = ?
- 18 − 5 = ? ✓
- ? = 5 + 18
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- 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?
- '11' ✓
- Use addition or subtraction to solve this problem. Laura has 12 books and Jacob have 8 books. How many books do they have together?
- '20' ✓
Worksheet
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Presentation
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Lesson Details
Key learning points
- Addition facts within ten can be applied to addition within 20
- Subtraction facts within ten can be applied to subtraction within 20
- If 3 + 2 is equal to 5 then 13 + 2 is equal to 15
- 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 -
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