Fractions and decimals
Fair shares with water
Are two halves and four quarters really the same amount?
Watch first
See how a fraction and a decimal can be exactly the same amount.
What you need
Tick each one as you find it — 0 of 5 ready.
Stay safe: Wipe up water straight away — wet floors are slippery.
Plan the fair test
- Change: How many glasses you share the water between
- Measure: The amount in each glass
- Keep the same: Same 400 ml to start, same size glasses, same jug for measuring
Objectives this evidences
- Recognise and show, using diagrams, families of common equivalent fractions
- Add and subtract fractions with the same denominator
- Solve simple measure and money problems involving fractions and decimals to two decimal places
Do it, one step at a time
Step 1 of 5
- Step 1. Measure 400 ml of coloured water into the jug and write the total down.
- Step 2. Pour it into two glasses so they look equal, then measure each one back. Record both amounts.
- Step 3. Start again and share the same 400 ml between four glasses. Measure each and record.
- Step 4. Add the four amounts together. Compare the total with your starting 400 ml.
- Step 5. Write each share as a fraction of the whole and as a decimal of a litre: 200 ml is one half, or 0.2 of a litre.
What should happen
Two lots of 200 ml and four lots of 100 ml both come back to 400 ml. Eyeballing 'equal' is usually a few millilitres out.
Think about: Your four amounts probably did not total exactly 400 ml. Where did the missing water go?
Write up your result
A sentence or two is enough to save it.
The lessons behind this practical
Each one opens with the same short film, and the film has a written transcript underneath if reading is easier than watching.
Now the quiz for this topic
Questions come from the lessons behind this practical, so nothing is asked that has not been taught.
Quiz
Fractions and decimals quiz
10 questions from the lessons in this stage. No timer, and you can try again as many times as you like.