New
New
Simple interest calculations with technology
I can carry out simple interest calculations with a calculator.
Lesson 7 of 11
New
New
- Year 10
Simple interest calculations with technology
I can carry out simple interest calculations with a calculator.
Lesson details
Key learning points
- Calculators are very useful here as they can be programmed efficiently.
- This saves time and can reduce error.
- It is also quick to reverse the process to find the original amount.
- The use of a multiplier ensures greater efficiency.
Keywords
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
A single digit percentage is incorrectly worked out by dividing by 10 and not 100 e.g 3% = 0.3, e.g. 0.54% = 0.054
Dividing the percentage by 100 gives the decimal equivalent i.e 0.54% = 0.0054
If pupils had £x in their bank account, what simple interest rate (<6%) per year and number of years would be needed to double this amount? This allows pupils to understand the product of the rate and years needing to be 1. For a challenge, give examples of S.I and years for tripling the amount.
Teacher tip
Licence
This content is © Oak National Academy Limited (2025), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).
Lesson video
Loading...
Prior knowledge starter quiz
6 Questions
Q1.If I increase £45 to £126, what is the percentage gain?
If I increase £45 to £126, what is the percentage gain?
Q2.Find 52% of 800
Find 52% of 800
Q3.A data analyst celebrates his investment increasing by 14% which is now worth £1094.40. How much did he originally invest?
A data analyst celebrates his investment increasing by 14% which is now worth £1094.40. How much did he originally invest?
Q4.Increase 11 by 15%
Increase 11 by 15%
Q5.If I decrease £48 to £12, what is the percentage loss?
If I decrease £48 to £12, what is the percentage loss?
Q6.If I increase £75 to £97.50, what is the percentage gain?
If I increase £75 to £97.50, what is the percentage gain?
Assessment exit quiz
6 Questions
Q1.What is the amount of simple 1.3% interest earned on an investment of £400 over 6 years?
What is the amount of simple 1.3% interest earned on an investment of £400 over 6 years?
£34.20
£32.23
Q2.What is the amount of simple 1.6% interest earned on an investment of £500 over 4 years?
What is the amount of simple 1.6% interest earned on an investment of £500 over 4 years?
£32.78
£32.50
Q3.What is the amount of simple 2.8% interest earned on an investment of £638 over 10 years?
What is the amount of simple 2.8% interest earned on an investment of £638 over 10 years?
£202.91
£178.64
Q4.What is the amount of compound 2.8% interest earned on an investment of £638 over 10 years?
What is the amount of compound 2.8% interest earned on an investment of £638 over 10 years?
£178.64
£178.64
Q5.What is the amount of compound 4.9% interest earned on an investment of £230 over 8 years (to 2 d.p.)?
What is the amount of compound 4.9% interest earned on an investment of £230 over 8 years (to 2 d.p.)?
Q6.What is the amount of compound 2.3% interest earned on an investment of £1000 over 20 years (to 2 d.p.)?
What is the amount of compound 2.3% interest earned on an investment of £1000 over 20 years (to 2 d.p.)?
