Use known facts to find complements to 100 efficiently
Lesson details
Learning outcome
I can use known facts to find complements to 100 efficiently.
Key learning points
- Number facts to 10 can be applied to multiples of 10
- Using pairs to 10 and pairs to 100 we can find pairs to 100
- If we have a pair to 10 then the tens have to total 90 for the whole to be 100
- A number line can represent the complements to 100
Keywords
Complement to 100 - Pairs of numbers which total 100
Total - The result of adding.
Common misconception
Pupils may be less efficient if they are not fluent with bonds within 10 e.g. 3 + 6 = 9
Provide additional scaffolding as appropriate including examples of pairs that total 9 and 10
Teacher tip
Partitioning numbers practically can be useful initially in this lesson however pupils should be encouraged to visualise and work more abstractly as they become more confident in generalising about complements to 100
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.What is the total of 60 and 40?
Q2.Which of these 2-digit numbers is a multiple of ten?
Q3.What is 100 subtract 4?
Q4.100 = 92 +
Q5.Jacob has 75 football cards and wants 100 football cards. How many more football cards does he need?
Q6.100 subtract equals 97
Assessment exit quiz
6 Questions
Q1.Which one is not a complement to 100?
Q2.What is the total of 67 + 33?
Q3.Match the complements to 100
Q4.What do you add to 71 to make 100?
Q5.Complete the sentence: When the ones digits total 10 and the tens digits total the two 2-digit numbers are complements to 100
Q6.55 + 55 = 100. Why is this calculation incorrect?
To help you plan your 3 maths lesson on: Use known facts to find complements to 100 efficiently, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 3 maths lesson on: Use known facts to find complements to 100 efficiently, 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 2 maths lessons from the Securing place value to 100 and applying to addition and subtraction unit, dive into the full primary maths curriculum, or learn more about lesson planning.