Checking and securing understanding of percentage decrease
Lesson details
Learning outcome
I can decrease an amount by a given percentage.
Key learning points
- In all of these representations a single multiplier can be used to find a percentage decrease.
- Representation can help when you are not using a calculator.
- A multiplier is significantly faster when using a calculator.
- To decrease you are going below the original amount.
Keywords
Proportion - If two things are proportional then the ratio of part to whole is maintained and the multiplicative relationship between parts is also maintained.
Common misconception
When using multipliers, pupils can mistake a decimal for the percentage decrease. e.g. 0.52 is a 52% decrease, rather than recognising a 48% decrease
Reminding students that a decimal multiplier greater than 1 means an increase, and a decimal multiplier less than 1 means a decrease. The latter requires a subtraction from 1 or 100%
Teacher tip
To embed the fact that many questions can be the same but written indifferent ways, get pupils to write as many different questions to a calculation on MWB e.g 0.65 x 500 = 65% of 500 = 500 decreased by 500. Conversely, when an answer is 0.52, this says it is a decrease of 48% of 52% of an amount.
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Increase 600 by 5%
Q2.Write 62 as a percentage of 200
Q3.Increase 90 by 11%
Q4.Find 11% of 700
Q5.Write 50 as a percentage of 1250
Q6.Find 90% of 625
Assessment exit quiz
6 Questions
Q1.Which statement is the equivalent of "Decrease 50 by 20%"?
Q2.Which statement is the equivalent of "Increase 130 by 15%"?
Q3.Which statement is the equivalent of "Decrease 700 by 35%"?
Q4.Decrease 700 by 4.5%
Q5.Increase 700 by 4.5%
Q6.Increase 700 by 18%
To help you plan your 10 maths lesson on: Checking and securing understanding of percentage decrease, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 10 maths lesson on: Checking and securing understanding of percentage decrease, 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 4 maths lessons from the Percentages unit, dive into the full secondary maths curriculum, or learn more about lesson planning.