Firefighters are strong and brave – and they need math, too. Here’s a secret about fire hydrants: the color tells you how fast they pump water. In one town, a red cap means the hydrant pumps less than 500 gallons per minute (GPM), orange means between 500-999 GPM, green means 1000-1499 GPM, and blue gushes 1500 GPM or more. This matters because 1 gallon of water puts out 3 square feet on fire. By the way, a hose spraying 300 gallons of water a minute can fill about 8 bathtubs at once!
Wee ones: Plug your sink, then turn on the water and count to 10. Turn it off. Is the sink a little full, halfway full, or mostly full?
Little kids: If a fire truck has 5 “attack lines” (hoses) and you hook on 1 more, how many lines does it have now? Bonus: Which pumps water faster, a red hydrant at 90 gallons per minute, or an orange hydrant at 600 gallons per minute?
Big kids: If a rug that’s 10 feet wide and 9 feet long is on fire, how many square feet is that? (Imagine 10 rows of 1-foot-wide squares, with 9 squares in each row.) Bonus: If a gallon of water can put out 3 square feet of fire, how many gallons do you need to put out that fire?
Answers:
Wee ones: Most sinks will be only a little bit full, but yours might be different!
Little kids: 6 attack lines. Bonus: The orange hydrant pumps faster.
Big kids: 90 square feet. Bonus: 30 gallons, which is almost 1 bathtub of water!
