Number (negative numbers): Above and Below
The Problem
A kingfisher was sat on a branch that was overhanging a river. It was preparing to catch some minnows (small fish). You can see a picture of the kingfisher opposite with the relative locations of the minnows and other features such as freshwater shrimp and (sadly) a piece of rubbish. You’ll notice that the surface of the river has been marked on a scale as 0 m and the depth of the river is 5 m.
Using the information in the picture, work with a partner to answer the questions below.
- How far might the kingfisher travel to catch the minnow that is closest to the river’s surface?
- How far might the kingfisher travel to catch the shrimp that is on top of the tin can?
- How far might the kingfisher travel to catch the minnow that is the closest to the riverbed and then return to the branch?
Did you know?
The kingfisher’s beak is so aerodynamic that the front of many Japanese bullet trains are modelled after it.
Visualising the Problem and Getting Started
Drake said, “I think the line directly above the line marked 0 m is 100 cm.”
Do you agree with Drake? How do you know?
