Choose the most efficient strategy to add two 3-digit numbers
I can choose the most efficient strategy to add two 3-digit numbers.
Choose the most efficient strategy to add two 3-digit numbers
I can choose the most efficient strategy to add two 3-digit numbers.
These resources will be removed by end of Summer Term 2025.
Lesson details
Key learning points
- By looking carefully at the addends, we can choose the most efficient addition strategy.
- Sometimes an adjusting strategy is the most efficient.
- Sometimes a redistributing strategy is the most efficient.
- Sometimes a partitioning and bridging strategy is the most efficient.
Keywords
Partition - Partitioning is the act of splitting an object or value down into smaller parts.
Adjust - When you adjust you make a small change to a number. This can make a calculation easier to solve mentally.
Redistribute / redistribution - Redistribution is where part of one addend is moved to another addend.
Efficient - Working efficiently means finding a way to solve a problem quickly whilst also maintaining accuracy.
Common misconception
Pupils will often know one method, such as partitioning, and stick to it without trying any others. Sometimes, some pupils will be very reluctant to move away from written methods such as columns.
Reinforce the idea of bravery and courage to try new methods. Remind them that efficiency is partly about speed and they might find that other methods only become quick with practice!
To help you plan your year 3 maths lesson on: Choose the most efficient strategy to add two 3-digit numbers, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your year 3 maths lesson on: Choose the most efficient strategy to add two 3-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 2 maths lessons from the Informal and mental strategies for adding and subtracting two 3-digit numbers unit, dive into the full secondary maths curriculum, or learn more about lesson planning.
Licence
Lesson video
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Starter quiz
6 Questions
30
60
4
100
Exit quiz
6 Questions
Adjustment
Redistribution
Partitioning