Math Through Sports
From fraction to decimal to percent
6 min · The same number wears three different outfits: 18/24, 0.75 and 75%.
- Percentages
- Decimals
The stat
The same number wears three different outfits: 18/24, 0.75 and 75%.
Learn the number
Completions
Attempts
A percent is just a fraction rewritten so the bottom number is 100. "Per cent" literally means "per hundred".
To get there, divide the top by the bottom. That gives a decimal. Multiply the decimal by 100 and you have the percent.
Completion percentage in football is exactly this: completions divided by attempts.
Read the stat
A quarterback completes 18 of 24 passes.
- Write the fraction: 18/24.
- Divide top by bottom: 18 ÷ 24 = 0.75.
- Multiply by 100: 0.75 × 100 = 75.
- Add the percent sign: 75%.
18 of 24 is 0.75, which is a 75% completion rate.
Your turn
A shooter makes 13 of 20 shots. Turn that into a decimal and then a percent.
Explain what it means
75% is a rate, not a count. It says nothing about whether he threw 24 passes or 240 — which is why the number of attempts always matters alongside the percent.
Make a prediction
Pick a quarterback and predict his completion percentage next game to the nearest 5%. Write the number down before kickoff.
Review what happened
Afterwards, work out the real percentage from his line. If you were 10 points off, was it a strange game, or was your starting number wrong?
Check your understanding
0 of 4 correct
Every question has to be right for this lesson to count as complete. Miss one and you can try it again.