Year 10 - Maths
Compound interest calculations with technology
Percentages
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This pupil-friendly study guide includes a unit summary, clear notes, common mistakes, and quick questions with answers.
Unit Summary
In this unit pupils will learn how to perform simple and compound interest calculations using percentages.
Lesson Summary
You will learn to carry out compound interest calculations with a calculator.
Key Notes
- 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.
Vocabulary To Learn
- Compound interest: Compound interest is the interest calculated on the original amount and the interest accumulated over the previous period.
- Exponential form: When a number is multiplied by itself multiple times, it can be written more simply in exponential form.
Common Mistakes To Avoid
- A single digit percentage is incorrectly worked out by dividing by 10 and not 100 e.g 3% = 0.3. This error continues when increasing amounts e.g increase 40 by 3% has a multiplier of 1.3
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
Calculators are very useful here as they can be programmed efficiently. This saves time and can reduce error.
2. Use this key word in a maths sentence and explain it clearly. 'Compound interest'
Compound interest is the interest calculated on the original amount and the interest accumulated over the previous period. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: A single digit percentage is incorrectly worked out by dividing by 10 and not 100 e.g 3% = 0.3. This error continues when increasing amounts e.g increase 40 by 3% has a multiplier of 1.3. Correction: Remind pupils that to covert a percentage into a decimal we divide by 100. This applies with increase too e.g 120% has a multiplier of 1.2.
More Lessons In This Unit
- Advanced problem solving with percentages Study Guide
- Calculating compound interest rates Study Guide
- Changing compound interest rates Study Guide
- Checking and securing understanding of finding a percentage Study Guide
- Checking and securing understanding of percentage decrease Study Guide
- Checking and securing understanding of percentage increase Study Guide
- Compound interest calculations Study Guide
- Percentage profit and loss Study Guide
- Problem solving with percentages Study Guide
- Simple and compound interest Study Guide
- Simple interest calculations Study Guide
- Simple interest calculations with technology Study Guide
Browse all guides in the Year 10 Maths guide library.