Subtract multiples of ten from 2-digit numbers
Lesson details
Learning outcome
I can use number facts to subtract multiples of ten from a two-digit number.
Key learning points
- When subtracting multiples of ten from a two-digit number, the tens digit changes but the ones digit stays the same.
- We can use number facts to help us subtract multiples of ten from a two-digit number.
Keywords
Multiples of ten - The numbers that are said when we count on in tens from zero. Multiples of ten always have a ones digit of zero.
Recombine - To add the parts of a number gained through partitioning the whole to reach the whole again.
Common misconception
Children may automatically count back in tens to subtract a multiple of ten.
Discuss efficiency and compare different methods. Use practical equipment to draw attention to the relationship between adding multiples of ten in two-digit numbers and the known facts they already possess.
Teacher tip
When recording the steps followed when subtracting, avoiding equations such as 56 - 20 = 50 + 6 - 20 = 30 + 6 = 36. At this stage, using both addition and subtraction signs when adding will not be familiar to the children and could confuse and distract from the focus of the equation.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.19 + 40 = ? How many tens is being added to 19 in this equation? tens
Q2.Look at the image. Which equation does it represent?
Q3.Match the known facts that will help to add multiples of 10
2 tens + 4 tens = 6 tens
50 + 30 = 80
40 + 50 = 90
Q4.What could we do to help solve this equation? 32 + 50 =
Q5.Which of these equations will have the same sum as 54 + 40 = ?
Q6.33 + 40 =
Assessment exit quiz
6 Questions
Q1.Look at the number line. What equation is it showing?
Q2. 86 − 50 = ? How many tens are being subtracted from 86 in this equation? tens
Q3.Which of the images represent this equation? 82 − 40 =
Q4.Match the known facts that will help to subtract multiples of 10
5 tens − 2 tens = 3 tens
80 − 60 = 20
90 − 40 = 50
Q5.What could we do to help solve this equation? 75 − 30 =
Q6.86 − 60 =
To help you plan your 2 maths lesson on: Subtract multiples of ten from 2-digit numbers, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 2 maths lesson on: Subtract multiples of ten from 2-digit numbers, 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 Adding and subtracting ones and tens to and from 2-digit numbers unit, dive into the full primary maths curriculum, or learn more about lesson planning.