Solve problems explaining which strategy is most efficient
Lesson details
Learning outcome
I can solve problems, explaining which strategy is most efficient.
Key learning points
- We know different strategies for addition and subtraction including mental and written strategies.
- Looking at the numbers helps us see which strategy is most efficient.
- Missing number problems can be rearranged to identify an efficient strategy to solve the problem.
Keywords
Subtrahend - The subtrahend is the number to be subtracted. It is the second number in a subtraction.
Efficient - Being efficient means finding a way to solve a problem quickly whilst also maintaining accuracy.
Common misconception
Children may automatically resort to the use of the formal column algorithms. These are not always the most efficient methods.
What do you notice about the numbers? Is there a mental strategy that you could use?
Teacher tip
Children need to be encouraged to slow down and look at the numbers in each calculation and to reason about which strategy they would use and to reason about why.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Use an efficient method to find the sum of 14,875 and 3,123
Q2.Use an efficient method to find the sum of 9,308 and 5,245
Q3.Match the expression to the correct difference.
Q4.Use a number line to calculate 50,000 − 34,995 =
Q5.Use the ‘constant difference’ strategy to calculate 15,000 − 2,375 =
Q6.Two numbers have a total of 367,200 If one of the numbers is 320,000 what is the other number?
Assessment exit quiz
6 Questions
Q1.Match these expressions to the strategy you would use to calculate them.
Q2.A charity needs to raise £200,000 and it has already raised £57,306 Which strategy is most efficient to use to calculate how much more money it needs to raise?
Q3.A charity raises £246,803 in a fundraising event. It then raises another £1,907,368 Which strategy is most efficient to use to calculate how much money it has raised in total?
Q4.Find the missing number in this equation.
508,914 = + 205,730
Q5.Calculate the multi-step equation. Think about the strategy which will be most efficient.
205,677 + 499,998 − 200,000 =
Q6.Two numbers have a total of 1,690,768 and a difference of 999,412
What are the two numbers? 345,678 and
To help you plan your 6 maths lesson on: Solve problems explaining which strategy is most efficient, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 6 maths lesson on: Solve problems explaining which strategy is most efficient, 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 Rounding and solving problems with numbers up to 7 digits unit, dive into the full primary maths curriculum, or learn more about lesson planning.