### Video Transcript

What is the mass of the
basketball?

In this question, we have to find
the mass of the ball. But there’s a problem. There’s a ball and a cube or a box
on the measuring scale. This scale tells us the mass of the
box and the ball together. The dial on the scale is pointing
to the number 600. So we know the mass of the box and
the ball is 600 grams.

On the second set of scales,
there’s just the cube. The dial on the scale is pointing
to the number 400, which means the mass of the cube is 400 grams. So we have to find the difference
between 600 grams and 400 grams. What is 600 take away 400? It’s 200.

If the mass of the cube and the
ball together is 600 grams and the mass of the cube on its own is 400 grams, then
the mass of the ball on its own is 200 grams. To find the mass of the ball, we
subtracted 400 from 600. The mass of the ball is 200
grams.