Home | Lesson Archive | Year 3 Maths Archive | L2: Singapore's otters

# Fractions of quantities: L2: Singapore's otters

## The Lesson

In this exciting lesson, you will have an opportunity to show your understanding of halves, thirds, quarters and fifths, whilst solving a variety of fraction problems that relate to the fascinating clip that you watched at the start of the lesson and the animals that it featured.

Useful prior knowledge:

• To know what is meant by the numerator and the denominator in a unit fraction.
• To be able to recognise a half (1/2), a third (1/3), a quarter (1/4) and a fifth (1/5).
• To be able to calculate unit fractions of small quantities (e.g. 1/2 of 8, 1/4 of 12 etc.)

Did  you know?

Smooth-coated otter pups are blind and helpless at birth. Their eyes only open at around four weeks. At six weeks, they start learning how to swim.

## Whiteboard Challenges

Divide the bars and draw counters to solve the problems below.

A group (bevy) of 15 smooth-coated otters were wandering the through the backstreets, gardens and parks of Singapore.

1) 1/3 of the otters in the group were adults and the rest were pups.

How many adult otters were there?

2) 1/2 of the pups were less than 3 months old.

How many pups were less than 3 months old?

3) 1/5 of this entire otter group ganged together and chased after a dog!

How many otters in this group chased after a dog?