Grade 4 - Progress in Mathematics

Chapter 14 459

Negative Numbers

0 sea level

Stalagmite Garden

5-Mile Trail

Blue Grotto

Bottomless Pool

Stalactite Chamber

Pirate’s Rest

The Maze

20 ft

40 ft

60 ft

80 ft

100 ft

120 ft

Numbers that are written with a minus sign,

such as 
6, 
25, and 
247, are called

negative numbers. Negative numbers are

less than zero.

Yo u already know how to use negative

numbers to write temperatures below zero.


 15 F 
 3 C

Yo u can also use negative numbers to show

distances below sea level.

5 ft means “5 feet below sea level.”

The scale at the right shows

the location of different sites in

Crystal Caverns.

Solve. Use the scale of Crystal Caverns.

1. Which site is located at
   90 ft?


2. About how many feet below
   sea level is Stalagmite Garden?


3. Which site is farthest below
   sea level? About how many
   feet below sea level is it?


4. How many feet difference is
   there between Bottomless Pool
   and Stalactite Chamber?


5. Which site is halfway between
   sea level and Pirate’s Rest? How
   many feet below sea level is it?


6. Suppose there was a site at
   150 ft.
   How much lower than sea level would
   it be than Bottomless Pool?

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