Question

A bird was sitting on a branch 1½ feet above the surface of a lake. The bird saw a fish and dove 2¼ feet straight down to catch it. Explain how you would use the number line below to find the depth, in feet, of where the birth caught the fish

Answer 1

`\begin{gathered} 1\cdot(1)/(2)=(2+1)/(2)=(3)/(2)=1.5ft \\ 2\cdot(1)/(4)=(8+1)/(4)=(9)/(4)=2.25ft \end{gathered}`

Since the bird is above the surface we assume its value as positive

1.5ft

and since the fish is below the surface we assume its value as negative

-2.25ft

Now, using the number line: