Measure length and height from zero using whole m or cm | Exit Quiz | Oak National Academy

The result of subtracting one number from another is known as {{ }}

• a metre.

• the difference.

• a centimetre.

Answer explanation

Correct! When we subtract one number from another, the resulting number is known as the difference.

Which unit would you use to measure the height of a giraffe?

• mm

• cm

• m

• kg

Answer explanation

Correct! A giraffe is taller so we need to measure in a unit that is longer.

Match the calculation to the difference.

• 12 cm - 5 cm =

• 11 cm

• 20 cm - 8 cm =

• 6 cm

• 17 cm - 6 cm =

• 9 cm

• 14 cm - 8 cm =

• 12 cm

• 15 cm - 6 cm =

• 7 cm

Answer explanation

Correct! When we subtract, we are finding the difference.

What is the length of this feather?

(a)  

Answer explanation

Correct! The feather starts at zero and ends at 6 cm. The length of the feather is 6 cm.

What is the length of the pencil?

• 3 cm

• 6 cm

• 9 cm

Answer explanation

Correct! The object is not at zero, so we need to find the difference. 9 cm - 3 cm = 6 cm. The pencil is 6 cm long.

Jacob has broken his ruler and he can't see the zero. How can he measure the length of the leaf?

• He can't.

• Place the leaf at the end of the ruler and read the measurement as usual.

• He can use it but he needs to find the difference.

Answer explanation

Correct. To measure the length of the leaf, because it is not able to be placed at zero, he needs to find the difference.