How can the vertical number line be used to add or subtract

A vertical number line resembles a thermometer. It emphasizes that we count up in the number system.  Vertical number lines are just alternative way to look at the numbers.

This is commonly used in adding or subtracting

For example: 5 – 3

5 is the start, the sign determines whether you go down or go up, the minus sign denotes down then so the last number denotes how many steps you are going down where you land is the answer. The same goes with addition but instead of down, the plus sign denotes going up.

30 miles

step-by-step explanation:

we know that 60 seconds equals 1 minute and 60 minutes 1 hour

44 ft       60 sec     60 min     158400   ft

  *   *   =

1 sec       1 min       1 hour         hour

we know that there are 5280 ft per mile

158400   ft       1 mile         30 miles

  *   =

1   hour               5280 ft     1 hour

so in 1 hour   it can travel 30 miles

3000000000000000000000