Find the missing part when subtracting two-digit numbers
Lesson details
Learning outcome
I can solve missing number equations involving subtracting two-digit numbers.
Key learning points
- The parts and the whole can be rearranged to help us solve equations.
- A bar model or a part-part-whole model can be used to help understand missing number equations.
- Addition can be used to check subtraction equations.
- Addition can be used to solve missing number subtraction equations.
Keywords
Part - A piece or section of a whole.
Whole - All of something; complete.
Common misconception
When presented with missing number equations with larger numbers, children may not automatically make the link to the part-part-whole structure.
Use visual representations to consolidate understanding and to encourage children to manipulate the numbers or equations involved so they can utilise what they already know.
Teacher tip
This lesson involves building upon prior knowledge to deepen understanding of the structure of subtraction equations. Children are encouraged to manipulate individual numbers in equations in order to encourage confidence and mentally flexibility.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which of the following equations will result in a multiple of 10?
Q2.Which number line could be used to solve the equation shown? 73 − 36 = ?
Q3.Use the pattern to predict the answer to the next equation.
Q4.Use the pattern to predict the next equation in the sequence. The next equation will be
Q5.Write a subtraction equation, then solve it to find the missing part in the bar model.
Q6.Match each equation to the number that correctly completes it.
37
43
57
Assessment exit quiz
6 Questions
Q1.Which equation has a whole that is a multiple of 10
Q2.Which bar model represents the equation shown? 43 = 60 − ?
Q3.Write the addition equation you would use to check this subtraction. 57 − 33 = 24
Q4.Which number would solve the equation. 76 − = 23
Q5.Which bar model would represents the equation shown? − 42 = 25
Q6.Solve the equation − 42 = 29
To help you plan your 2 maths lesson on: Find the missing part when subtracting two-digit numbers, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 2 maths lesson on: Find the missing part when subtracting two-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 Addition and subtraction of two 2-digit numbers unit, dive into the full primary maths curriculum, or learn more about lesson planning.