NCERT Solutions for Class 4th The World Around Us Chapter 7 Which spinner spun properly? — Discuss
Book page 108 Updated on2026-09-19
Q1.
Which of the spinners did not spin properly? Discuss the possible reasons.
Answer
The spinner with the toothpick away from the centre did not spin properly. It wobbled and fell over quickly.
Set-up: push a toothpick through a piece of card. These are the four spinners to make.
Possible reasons we discussed:
The two sides of the card around the stick are not the same. One side is bigger and heavier.
The heavier side keeps pulling down, so the spinner leans over as it turns.
The toothpick below the card may be too long or bent, so the spinner does not rest on one small point.
The card may not be sitting flat and straight on the toothpick.
Why it happens: A spinner keeps turning only when it is balanced — the same on every side of the stick.
Q2.
Have you noticed the position of the hole in the first two spinners? Did this difference in the position of the hole make a difference in the spinning of these spinners?
Answer
Yes, the position of the hole made a big difference.
Set-up: push a toothpick through a piece of card. These are the four spinners to make.
Spinner
Where the hole is
What happened
First spinner
At the centre
It stayed upright and spun well
Second spinner
Away from the centre
It wobbled and fell over soon
The book says it plainly: the first spinner, with a hole at the centre, appears to be the same from all sides. This spinner remains upright and spins, but that is not the case with the second spinner.
Why it happens: When the hole is at the centre, the card on both sides of the stick is equal, so nothing pulls the spinner to one side.