Use number facts to add or subtract a one-digit number and a two-digit number.
Lesson details
Learning outcome
I can add and subtract a single digit number and a two-digit number.
Key learning points
- Known facts can be used to help solve equations with larger numbers.
- Partitioning a two-digit number into tens and ones can help with seeing the pattern in the ones.
- When adding to or subtracting from the ones without crossing the tens boundary, the tens digit does not change.
Keywords
Equation - An equation has an equal sign. It shows that what is on the left of the equation is equal to what is on the right.
Common misconception
Children may not recognise known facts when addends are presented in different order, e.g. they may not use 7+1 to solve 61 +7 They may also confuse tens and ones digits.
Focus on efficient ways of working and, when working in the abstract, partition the two-digit number into tens and ones, so the tens and ones digits can be easily identified and the commutative aspect of the ones digit can be more easily seen.
Teacher tip
Do not include additions which sum to a multiple of ten or subtractions from a multiple of ten as these will be covered separately. When giving problems, also give the solution rather than asking children to solve, so that they maintain focus on the structure of the problem.
Licence
Lesson video
Loading...
Prior knowledge starter quiz
6 Questions
Q1.Which decade is missing on the number line?
Q2.Alex subtracts 1 from these Base 10 blocks. Which image shows the number he now has?
Q3.Alex taps one more than the number shown. What number does he tap?
Q4.Which number is missing?
Q5.Which of the following could be Sam’s number?
Q6.Alex thinks of a two-digit number. It is 1 less than a multiple of ten. It is greater than 80 but less than 90 What is his number?
Assessment exit quiz
6 Questions
Q1.Which equation would come next in the pattern?
Q2.Which known fact could be used to solve the equation shown on the number line?
Q3.Which of the following equations can be solved using the known fact 3 + 5 = 8?
Q4.Which number will make both of the following equations correct?
Q5.Match the missing number equations to the correct answer.
Q6.What number did Alex add?
To help you plan your 2 maths lesson on: Use number facts to add or subtract a one-digit number and a two-digit number., download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 2 maths lesson on: Use number facts to add or subtract a one-digit number and a two-digit number., 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.