Basic Math for Fire Ground Hydraulics

Question 1

the driver/operator should round to the nearest hundredth (two decimal places).
25.232 – rounded = 25.23 25.236 – rounded = 25.24

Answer 1

Rounding

Question 2

To square a number simply multiply a number by itself.
Example: 32 = 3 x 3 = 9 Shortcut for squaring half numbers, such as (2.5) 2, (4.5) 2, (7.5) 2; identify the two whole numbers that the half number is between.
2.5 is between 2 and 3
Multiply those two numbers together.
2 x 3 = 6
Add 0.25 to that total.
6 + 0.25 = 6.25

Answer 2

Squaring Numbers

Question 3

Fractions can be converted into decimals by dividing the numerator (top number) by the denominator (bottom number). 1/2 = 1 ÷ 2 = 0.5 15/16 = 15 ÷ 16 = 0.9375 which is rounded to 0.94

Answer 3

Converting Fractions into Decimals

Question 4

to use the diameter of a hose line and its length in the same equation in order to determine proper pressure. It is not possible to use “3 inches” and “200 feet” in the same equation. Instead, one of the two (units) need to be converted to the other in order to solve the equation.
In this example, “3 inches” will be converted into feet.
3” ÷ 12” = 0.25’ (12 is the number of inches in a foot)
In this example, “2 feet” will be converted into inches.
2’ x 12” = 24” (12 is the number of inches in a foot)

Answer 4

Converting Inches and Feet