Simple interest calculations
Lesson details
Learning outcome
I can carry out simple interest calculations.
Key learning points
- Simple interest is calculated once and then added repeatedly.
- By considering the calculations for simple interest, you can be more efficient.
- Through understanding the structure, you can reverse the calculations to find the original amount.
Keywords
Rate of interest - The rate of interest is the percentage by which an amount increases
Simple Interest - Interest is money added to savings or loans. Simple interest is always calculated on the original amount
Compound interest - Compound interest is the interest calculated on the original amount and the interest accumulated over the previous period.
Common misconception
Pupils should pay careful attention to what the question asks. Working out the overall amount after a simple or compound increase is different to working out the total interest only.
Pupils can underline or highlight the key instruction to the question e.g. Total amount or total interest, to remind them of the need to subtract from the original amount or not.
Teacher tip
Pose the question, "If you have £100 in a bank account that offered x% simple interest rate per year over y years, how many different examples of x and y can pupils give so the overall money in the account is £180?"
Licence
Lesson video
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Prior knowledge starter quiz
6 Questions
Q1.Which statement is the equivalent of "Increase 76 by 30%"?
Q2.If I increase £90 to £99, what is the percentage gain?
Q3.If you invest £500 for three years and receive 2% simple interest each year, how much will you have at the end?
Q4.If I increase £70 to £86.10, what is the percentage gain?
Q5.Which statement is the equivalent of "Decrease 130 by 40%"?
Q6.If I increase £80 to £86.40, what is the percentage gain?
Assessment exit quiz
6 Questions
Q1.If I invest £400 over 3 years at 2% interest, I have £424. Is this simple or compound interest?
Q2.If I invest £600 over 2 years at 2.5% interest, I have £630.38. Is this simple or compound interest?
Q3.If I invest £1500 over 5 years at 1.9% interest, I have £1642.50. Is this simple or compound interest?
Q4.If I invest £10 over 2 years at 4% interest, I have £10.80. Is this simple or compound interest?
Q5.If I invest £46.21 over 1 year at 4% interest, I have £48.06. Is this simple or compound interest?
Q6.Which investment results in more money at the end: an investment of £30 at a rate of 2% simple interest for 4 years, or £30.50 at a rate of 3.5% compound interest for 2 years?
To help you plan your 10 maths lesson on: Simple interest calculations, download all teaching resources for free and adapt to suit your pupils' needs...
To help you plan your 10 maths lesson on: Simple interest calculations, 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.