Use a decimal measure
If a ribbon is 1.25 m long and another is 0.75 m, together they measure 2.00 m.
Line the decimal places up carefully.
Year 5
Solve problems involving numbers up to three decimal places, percentages and decimal equivalents of fractions
Solve practical problems using decimals, percentages and common decimal equivalents of fractions.
Lesson overview
Number - decimals and percentages
Decimals and percentages appear in measures, money and quantities. Solving these problems means choosing the right representation and using place value carefully to keep the amounts sensible.
Use a percentage of 100
35 per cent of 100 is 35.
Per cent means parts per hundred.
Use a known fraction equivalent
0.5 of 20 is the same as of 20.
Known decimal and fraction equivalents can make problems easier.
Worked example
A drink bottle holds 0.75 litres. How much do 4 bottles hold?
- Each bottle holds the same amount.
- Multiply 0.75 by 4.
- Three quarters taken four times makes 3 wholes.
- The bottles hold 3 litres altogether.
Round 1: Learn it
Choose whether the problem is using decimals, percentages or a known equivalent.
Finish this round to unlock Round 2: Show you know it.
Question 1
What is 1.25 + 0.75?
Question 2
What is 35 per cent of 100?
Question 3
What is 0.5 of 20?
Question 4
A bottle holds 0.75 litres. How much do 4 bottles hold?
Question 5
Which decimal equals 25 per cent?
Common mistakes
Watch for these as you work through the lesson.
- Adding or subtracting decimals without lining up the decimal points.
- Forgetting that per cent means out of 100.
- Not spotting a helpful fraction-decimal equivalent.
Related topics
These ideas connect closely to this lesson.
- Read, write, order and compare numbers with up to three decimal places.
- Recognise the per cent symbol and understand that per cent relates to number of parts per hundred, and write percentages as a fraction with denominator 100 and as a decimal.