NCERT Solutions for Class 4th The World Around Us Chapter 7 Making spinners and testing them — Activity 2
Book page 106–107 Updated on2026-09-19
Q1.
Collect things, such as pieces of cardboard, toothpicks, an empty tube of a ballpoint pen, and other small objects. Make the following spinners. Spin them and record your observations.
Answer
What to do
Cut two round pieces and one square piece from thick cardboard, each about as wide as your palm.
Make a small hole in the centre of the first round piece. Push a toothpick through it so a little of the toothpick sticks out below.
Make the hole away from the centre in the second round piece and push a toothpick through it.
Push a toothpick through the centre of the square piece.
Take one more round piece with the toothpick at the centre, and draw a small dark mark near its edge.
Spin each one on a table and write down what you see.
Set-up: push a toothpick through a piece of card. These are the four spinners to make.
The completed table
Change in the spinner
What do you observe? (spins/does not spin)
Any other observations
Toothpick at the centre
Spins
It stands upright and spins for a long time. It looks the same from all sides.
Toothpick away from the centre
Does not spin properly
It wobbles at once and falls over very soon.
A square spinner
Spins
While it is spinning it looks round, not square.
Circular spinner with a circular mark on its body
Spins
The mark is no longer seen as a dot. It looks like a ring going round and round.
Any other — a triangular spinner
Spins
It also looks round while spinning, just like the square one.
Why it happens: A spinner spins well when the stick is at its centre, because then both sides of the card weigh the same and it stays upright.
Tip: If your spinner still wobbles, try a shorter toothpick below the card, or push the card so it sits flat and straight on the stick.