Add 2-digit numbers when crossing the tens boundary
I can add two-digit numbers when the sum crosses the tens boundary
Add 2-digit numbers when crossing the tens boundary
I can add two-digit numbers when the sum crosses the tens boundary
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- When adding two-digit numbers that cross the tens boundary, both addends can be partitioned, then recombined.
- When adding two-digit numbers that cross the tens boundary, one addend can be partitioned. This is more efficient.
- A number line can be used to find a missing addend when the tens boundary is crossed.
Keywords
Partition - To split a whole up into parts; a piece or section of a whole.
Common misconception
If children partition both addends when addition involves bridging 10, they may forget to add the extra 10 made when combining the ones.
Encourage children to consider whether an addition will bridge 10 before solving and if so, partition only one addend to reduce the number of steps required, increasing efficiency.
To help you plan your year 2 maths lesson on: Add 2-digit numbers when crossing the tens boundary, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 2 maths lesson on: Add 2-digit numbers when crossing the tens boundary, 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.
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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 secondary maths curriculum, or learn more about lesson planning.
Licence
Starter quiz
6 Questions






Exit quiz
6 Questions


