3
Halves, and not halves
Learner’s Book 1: Unit 3, pp. 51–52
GoalTell shapes that are cut into halves from shapes that are not, and draw the other half to make a whole.
New words
fold · bend something so one part lies on top of the othermatch · fit exactly on top of each othernot equal · not the same size
Explanation
There is a way to check a half. Imagine folding the shape along the line. If the two parts fit exactly on top of each other, they match, and they are halves. If one part sticks out, they do not match, so they are not halves. A line near the edge of a shape makes a small part and a big part. That is not halves. Sometimes you only have one half, like half of a rocket. You can draw the other half on the other side of the line. It is the same size, like a mirror.
Worked examples
Fold this rectangle along the line. The top part fits exactly on the bottom part. They match, so they are halves.
This square has a line near one side. The parts would not match if we folded it. They are not halves.
Here is the left half of a rocket next to a line: half of the pointed top, a round window and one fin. Draw the other half on the right of the line, the same size. Now it is a whole rocket.
Class activity
Mirror picture: fold a paper in half and open it. Draw half of a simple vase or a tree next to the fold line. Then draw the other half on the other side, the same size. Fold again to check that the two halves match.
Practice
1
Is this rectangle cut into halves?
Yes. The two parts are equal.
2
Is this square cut into halves?
No. The parts are different sizes.
3
You fold a paper along a line and the two parts fit exactly. Are they halves?
Yes.
4
You have drawn the left half of a butterfly. How do you draw the right half?
On the other side of the line, the same size, like a mirror.