Year 1: One half of a shape
Part of the Year 1 halves and quarters chapter. Chapter overview · whole chapter on one page · Download worksheet (PDF) · Answers (PDF)
One half of a shape
A half is one of two equal parts. If you share a shape into two equal parts, each part is one half. We say “one half”.
Two halves make one whole. A shape can be cut across the top and bottom, or down the middle.
Key ideas
- A half is one of two equal parts.
- Two halves make one whole.
- The parts must be the same size to be halves.
Method. One half is one of 2 equal parts. Check the parts and the shading.
- Count the parts. One half needs 2 equal parts.2 parts
- Check the parts are the same size. Equal parts are the same size.The parts are the same size.
- Count the shaded parts. We need exactly one shaded part for one half.1 shaded
- Decide. Yes. The shaded part is one half.
Check. Say it in words: the shaded part is one half. ✓
Watch out. Parts must be the same size before you can call them halves or quarters.
Method. One half is one of 2 equal parts. Check the parts and the shading.
- Count the parts. One half needs 2 equal parts.2 parts
- Check the parts are the same size. Equal parts are the same size.The parts are not the same size.
- Count the shaded parts. We need exactly one shaded part for one half.1 shaded
- Decide. No. The parts are not the same size, so the shaded part is not one half.
Check. Say it in words: the shaded part is not one half. ✓
Watch out. Parts must be the same size before you can call them halves or quarters.
Method. Look at each picture and find the one with one half shaded.
- Look at A. Count the equal parts and the shaded parts.A: 4 parts, equal, 1 shaded
- Look at B. Count the equal parts and the shaded parts.B: 2 parts, equal, 1 shaded
- Look at C. Count the equal parts and the shaded parts.C: 2 parts, not equal, 1 shaded
- Find the picture that matches. We want the picture with one half shaded.Matches: B
- Write the answer. B
Check. A and C do not match. ✓
Watch out. Count the equal parts first, then the shaded parts.
Watch out
Watch out: if you shade both parts, you have shaded the whole shape, not one half.
Exam tip
Grown-up tip. Cut a square of paper or a biscuit into two halves. Ask: “Are they the same size?” Then ask your child to point to one half.
Exercise 10B One half of a shape
Non-calculatorMethod. One half is one of 2 equal parts. Check the parts and the shading.
- Count the parts. One half needs 2 equal parts.2 parts
- Check the parts are the same size. Equal parts are the same size.The parts are the same size.
- Count the shaded parts. We need exactly one shaded part for one half.1 shaded
- Decide. Yes. The shaded part is one half.
Check. Say it in words: the shaded part is one half. ✓
Watch out. Parts must be the same size before you can call them halves or quarters.
Method. One half is one of 2 equal parts. Check the parts and the shading.
- Count the parts. One half needs 2 equal parts.2 parts
- Check the parts are the same size. Equal parts are the same size.The parts are the same size.
- Count the shaded parts. We need exactly one shaded part for one half.1 shaded
- Decide. Yes. The shaded part is one half.
Check. Say it in words: the shaded part is one half. ✓
Watch out. Parts must be the same size before you can call them halves or quarters.
Method. One half is one of 2 equal parts. Check the parts and the shading.
- Count the parts. One half needs 2 equal parts.2 parts
- Check the parts are the same size. Equal parts are the same size.The parts are the same size.
- Count the shaded parts. We need exactly one shaded part for one half.1 shaded
- Decide. Yes. The shaded part is one half.
Check. Say it in words: the shaded part is one half. ✓
Watch out. Parts must be the same size before you can call them halves or quarters.
Method. One half is one of 2 equal parts. Check the parts and the shading.
- Count the parts. One half needs 2 equal parts.2 parts
- Check the parts are the same size. Equal parts are the same size.The parts are the same size.
- Count the shaded parts. We need exactly one shaded part for one half.2 shaded
- Decide. No. All the parts are shaded, so this is the whole shape.
Check. Say it in words: the shaded part is not one half. ✓
Watch out. Parts must be the same size before you can call them halves or quarters.
Method. One half is one of 2 equal parts. Check the parts and the shading.
- Count the parts. One half needs 2 equal parts.4 parts
- Check the parts are the same size. Equal parts are the same size.The parts are the same size.
- Count the shaded parts. We need exactly one shaded part for one half.1 shaded
- Decide. No. The shape has 4 equal parts, not 2, so the shaded part is not one half.
Check. Say it in words: the shaded part is not one half. ✓
Watch out. Parts must be the same size before you can call them halves or quarters.
Method. One half is one of 2 equal parts. Check the parts and the shading.
- Count the parts. One half needs 2 equal parts.2 parts
- Check the parts are the same size. Equal parts are the same size.The parts are not the same size.
- Count the shaded parts. We need exactly one shaded part for one half.1 shaded
- Decide. No. The parts are not the same size, so the shaded part is not one half.
Check. Say it in words: the shaded part is not one half. ✓
Watch out. Parts must be the same size before you can call them halves or quarters.
Method. Look at each picture and find the one with one half shaded.
- Look at A. Count the equal parts and the shaded parts.A: 2 parts, equal, 2 shaded
- Look at B. Count the equal parts and the shaded parts.B: 2 parts, equal, 1 shaded
- Look at C. Count the equal parts and the shaded parts.C: 4 parts, equal, 1 shaded
- Find the picture that matches. We want the picture with one half shaded.Matches: B
- Write the answer. B
Check. A and C do not match. ✓
Watch out. Count the equal parts first, then the shaded parts.
Method. Each half is one of two equal parts. Two halves make one whole.
- Count the equal parts in the whole circle. Each half is one of the two equal parts.2 halves
- Think about how many make a whole. Two halves put together make the whole circle.1 half + 1 half = 1 whole
- Write the answer. 2
Check. Put two halves together: they make one whole circle. ✓
Watch out. Two halves make one whole. Do not say three.
Method. One part of two equal parts is one half.
- Count the equal parts. The cake is cut into two equal parts.2 equal parts
- Look at the part Sam ate. It is one of the two equal parts.One of 2 equal parts
- Write the answer. one half
Check. Two halves make the whole cake: one half and one half. ✓
Watch out. Use the words “one half” when you name one of two equal parts.
Method. Halves must be equal parts.
- Look at the two parts. The two parts here are not the same size.One part is bigger.
- Think about halves. A half is one of two equal parts.The parts must be equal.
- Write the answer. No. The two parts must be equal to be halves.
Check. Cutting in two does not always give halves. ✓
Watch out. Check the sizes before you say halves.
Method. Both rectangles are the same size. Each shaded part is one half of its rectangle.
- Look at rectangle A. One of the two equal parts is shaded.A: one half shaded
- Look at rectangle B. One of the two equal parts is shaded too.B: one half shaded
- Compare the two shaded parts. Both rectangles are the same size, so the halves are the same size.Same size
- Write the answer. Yes. Both shaded parts are one half of the same size rectangle.
Check. The shapes look different, but each shaded part is one of two equal parts. ✓
Watch out. The way a shape is cut does not change the size of a half.