# Number (estimation): Robin & Mole

## Challenge level ⭐

(designed for children with prior knowledge of the Year 3 programme of study)

Learning Objective

We are learning how to solve a natural world problem by using and applying our skills and knowledge of number and estimation.

Useful prior knowledge:

• Understanding of the terms at least, smallest and largest

https://www.bbc.co.uk/programmes/p04m09yk/player

Credit: BBC One - Life in the Snow

## Clip Description

Robins are welcome visitors to our parks and gardens all year round but especially in winter, when their cheery red breast can brighten up even the dullest of days. These small songbirds have a wingspan of around 20 centimetres (cm) and weigh just 18 grams (g).

In this fascinating clip, a robin is struggling to find juicy worms to eat. This is because it is winter and the ground has frozen solid. Fortunately, help is at hand in the form of a mole. Moles spend much of their time underground, also searching for worms. They move around by digging shallow tunnels, piling soil at the surface as they go. These piles, or molehills, are exactly what the robin needs as they are soft and easy to remove worms from.

## Quick Whiteboard Challenge

In the UK, the average length of an earthworm is around 15 cm.

Can you name two items that, when put next to each other, are about the same length as an average-sized earthworm?