Year 5 - Maths
Multiply tenths by whole numbers
Calculating with decimal fractions
Study Hub
Study Guides
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 explain the effect of multiplying and dividing a number by 10, 100 and 1,000 and use their knowledge of multiplying decimal fractions by whole numbers to solve measures problems.
Lesson Summary
You will learn to use known multiplication facts and unitising to multiply tenths by whole numbers.
Key Notes
- There are 10 tenths in one whole.
- Unitising can help to multiply tenths by whole numbers.
- Multiplication of tenths can be represented as repeated addition of tenths.
- '___ times ___ ones is equal to ___ ones so ___ times ___ tenths is equal to ___ tenths' supports us to multiply tenths.
Vocabulary To Learn
- Tenth: One-tenth is one part in ten equal parts.
Common Mistakes To Avoid
- Children may incorrectly write the amount of tenths e.g. 49 tenths may be written as 0.49
3 Quick Questions (With Answers)
1. Solve this in steps: explain the method from this lesson and why each step matters.
There are 10 tenths in one whole. Unitising can help to multiply tenths by whole numbers.
2. Use this key word in a maths sentence and explain it clearly. 'Tenth'
One-tenth is one part in ten equal parts. Use this word when showing your method, then check your final answer is reasonable.
3. Spot and fix this common maths mistake.
Mistake: Children may incorrectly write the amount of tenths e.g. 49 tenths may be written as 0.49. Correction: There are ten tenths in one whole. So e.g. 49 tenths is composed of 4 ones and 9 more tenths. We write this as 4.9.
More Lessons In This Unit
- Converting units of length Study Guide
- Converting units of mass and capacity Study Guide
- Divide decimal fractions by 1-digit numbers Study Guide
- Divide decimal fractions by 1-digit numbers using written methods Study Guide
- Explain how to multiply and divide a number by 10, 100 and 1,000 Study Guide
- Multiply 1-digit numbers by decimal fractions using written methods Study Guide
- Multiply 1-digit numbers by decimals Study Guide
- Multiply hundredths by whole numbers Study Guide
- Multiplying and dividing a number by 10, 100 and 1,000 Study Guide
- Multiplying and dividing a number by 10, 100 and 1,000 including bridging 1 Study Guide
- Predicting the size of a product Study Guide
- Solve measures problems using knowledge of multiplying decimal fractions Study Guide
- The relationship between multiplying by 0.01 and dividing by 100 Study Guide
- The relationship between multiplying by 0.1 and dividing by 10 Study Guide
Browse all guides in the Year 5 Maths guide library.