NCERT solutions for Math - Magic [English] Class 4 chapter 8 - Carts and Wheels [Latest edition]

You must have seen many such round things around you. List some more in your notebook.

Have you ever gone to a bangle shop?

Guess which of these bangles is of your size.

Take a wire and make a bangle for yourself. Can your madam or mother wear this bangle?

A bangle can be used to trace a circle. What are the other things around you that you can use to trace a circle?

Trace a circle with the help of some of these in your notebook or on the ground.

1. Which thing makes the smallest circle?
2. Which thing makes the biggest circle?
   

Do you play these games?

Which song do you sing when you play these?

Play these games in your school.

Why do we make a circle in each of these games?

What if a rectangle was made? Discuss.

Think of some other games you play by making circles.

Is any of these a good drawing of a circle?

Can you draw a circle on the floor with a chalk? Try.

Also draw a circle in your notebook using a pencil.

Look at the circles drawn by your friends. Who has drawn the best circle?

Do the activity in small groups. Each group should take a rope of a different length. See the circles made by different groups.

Which group made the smallest circle?

How long was their rope?

Does a longer rope make a bigger circle? Why is it so?

What was the radius of the smallest circle?

Draw the radius of this bangle using a ruler.

Measure the length of the radius.

Now see what your friends have drawn. Discuss the length of the radius they measured. Is it the same as yours?

Draw the radius of these circles. Guess which circle has the longer radius.

Measure the radius of both circles using a ruler.
Write the length of their radius.

1. Radius of the green circle ______
2. Radius of the blue circle ______

Measure the radius of the wheels of a bicycle or a bullock-cart. You can use a thread or a measuring tape.

Are all the wheels of a bicycle or a bullock-cart of the same radius?

Have you seen a tractor or a road roller?

Which is the biggest wheel you have ever seen?

Are all wheels of a tractor or road roller of the same radius?

Lali and Kali are tied to a pole with ropes. Kali has a longer rope. Who can look for more grass to eat?

Have you seen a compass before? How will you use this to make a circle?

- Open your compass.

- Press the tip of the compass on the paper. Hold the compass from the top.

- Without moving the tip, try to move the pencil around.

- Do you get a circle?

Is this circle better than the one you made earlier without a compass?

Draw the radius of this circle and measure it.

Now you can make your own designs like Daljeet had made. How many did you make?

Guess how this design has made. Use a compass to make similar one in the box.

Why did Naina get such a drawing? Discuss.

Can a circle have more than one centre?

Did any one of you ever get a shape like Naina’s?

Now you trace a circle on a paper using a bangle. Cut it. Then find its centre like Sameena did.

Can you balance a plate on your finger?

You also try to balance a plate or a round lid on your finger. Where does it balance?

Now everybody was excited to spin their tops which looked like this.

Zakir	Appu	Naina	Guddo

Whose top will not spin at all?

Now everybody was excited to spin their tops which looked like this.

Zakir	Appu	Naina	Guddo

Whose top will spin a little?

Now everybody was excited to spin their tops which looked like this.

Zakir	Appu	Naina	Guddo

Whose top will spin the best?

Now everybody was excited to spin their tops which looked like this.

Zakir	Appu	Naina	Guddo

In whose top is the stick nearest to the centre?

To make the top spin well, where will you make the hole?