Percents represent Parts of a Whole, like a fraction and a decimal.
I'm sure you recognize 50%, which equals 1/2 or .50 (often written as .5 or 0.5).
Let's first make an estimation.
If the football player completed 50% of his passes, that's half of 250 passes, which equals 125.
57.2% is just over half, so we know approximately the size of the number we're looking for.
Now let's do the math:
The question is asking:
"What is 57.2% OF 250"
To calculate a part of a whole, we simply multiply. In word sentences "OF" means to multiply.
Recall 50% is the same as .50 or .5.
57.2% = .572 (move the decimal two places to the left)
When you multiply 250 x .572 you will get: 143 completed passes.
Perhaps the next Peyton Manning. :-)