Measurement

Hong Kong

Stage 1

Lesson

We can use the length of an object to compare it with another object.

Once we have lengths of two or more objects we can compare them by looking at their lengths on a number line. When we're comparing lengths we usually want to know if one object is longer or shorter than another.

If we have a bus that is $11$11 metres long and a car that is $5$5 metres long we can find which one is shorter or longer by looking at them on a number line. First we have to place them on a number line in the right spot, then we can see which is further to the left or right. So here we have a car at the number $5$5, and a bus at the number $11$11.

Shorter objects will be further to the left on a number line. Longer or taller objects will have a number that is further to the right on a number line.

So we can say that the car is shorter than the bus. We can also say that the bus is longer than the car. Remember, a length can be any distance, so we can compare heights the same way we compare lengths.

A bee is $11$11 mm long. A fly is $13$13 mm long.

Which insect is shorter?

Fly

ABee

B

Glen is $165$165 cm tall. Valentina is $144$144 cm tall.

Who is taller?

Valentina

AGlen

B

Compare the heights of these birds to answer the following questions.

Which bird is the shortest?

Penguin

APelican

BOstrich

CWhich bird is the tallest?

Pelican

AOstrich

BPenguin

CWhich bird is closest to $100$100 cm in height?

Penguin

APelican

BOstrich

C