Use knowledge of subtraction facts within 10 to subtract within 20
Lesson details
Learning outcome
I can use knowledge of subtraction facts within 10 to subtract within 20
Key learning points
- Subtraction facts within ten can be applied to subtraction within 20, e.g. if 5 - 2 = 3 then 15 - 2 = 13
- A number line can be used to show the link between subtraction of one-digit numbers and teen numbers.
Keywords
Subtraction - To partition one part from another (the subtrahend from the difference), or to decrease an amount by taking an amount away.
Minus - A synonym for subtract, represented by the symbol -
Difference - The result of subtracting one number from another. How much one number differs from another.
Common misconception
Children may rely on counting strategies instead of using known facts to subtract from larger numbers.
Make comparisons between subtraction within 10 and within 20, looking for patterns. Make sure children notice that the ones digit stays the same when we subtract numbers with the same ones digits such as 5 - 2 and 15 - 2.
Teacher tip
Use number lines to show subtraction within 10 and within 20, drawing out the similarities. Make sure children notice that the ones digit stays the same when we subtract numbers with the same ones digits.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What is the missing part?
Q2.What could the two missing parts be?
Q3.Which of these symbols means minus?
Q4.Andeep has 5 biscuits and eats 3 of them. How many does he have left? Which equation represents this?
Q5.Izzy has 12 hair clips. 10 are pink and the rest are blue. How many are blue? hair clips
Q6.Sofia has 17 hair clips. She loses 7 of them. How many hair clips does she have now? hair clips
Assessment exit quiz
6 Questions
Q1.Which of these part-part-whole models match the story?
First Izzy had 19 strawberries and then she ate 5 of them. How many strawberries does she have left?
Q2.Which equation below helps you to find the answer to 13 − 2 = ___?
Q3.Complete the sentence: 7 minus 2 is equal to 5, so 17 minus 2 is equal to
Q4.Complete the sentence: 6 minus 3 is equal to 3, so 16 minus 3 is equal to
Q5.First, Izzy collected 18 stones. 5 stones are grey and the rest are brown. How many stones are brown? stones
Q6.First, Andeep had 15 stickers and then he gave Izzy 3 stickers. How many stickers does Andeep have now? stickers
To help you plan your 1 maths lesson on: Use knowledge of subtraction facts within 10 to subtract within 20, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 1 maths lesson on: Use knowledge of subtraction facts within 10 to subtract within 20, download all teaching resources for free and adapt to suit your pupils' needs.
The starter quiz will activate and check your pupils' prior knowledge, with versions available both with and without answers in PDF format.
We use learning cycles to break down learning into key concepts or ideas linked to the learning outcome. Each learning cycle features explanations with checks for understanding and practice tasks with feedback. All of this is found in our slide decks, ready for you to download and edit. The practice tasks are also available as printable worksheets and some lessons have additional materials with extra material you might need for teaching the lesson.
The assessment exit quiz will test your pupils' understanding of the key learning points.
Our video is a tool for planning, showing how other teachers might teach the lesson, offering helpful tips, modelled explanations and inspiration for your own delivery in the classroom. Plus, you can set it as homework or revision for pupils and keep their learning on track by sharing an online pupil version of this lesson.
Explore more key stage 1 maths lessons from the Composition of numbers 11 to 19 unit, dive into the full primary maths curriculum, or learn more about lesson planning.