"Per cent" is just two Latin words squashed together — per centum, meaning "for every hundred". So 50% means 50 out of every 100. That's the whole idea. A percentage is a fraction whose bottom number is always 100.
The Hundred-square
Picture a big square chopped into 100 little ones — that's the whole thing, all of it, 100%. Shade 25 of them and you've shaded 25%, which is the same as the fraction 25/100, which tidies up to one quarter. The number of shaded squares is the percentage. In the toy, click to shade and you'll see the percentage, the fraction, and the plain-English name all line up.
A Percentage of an Amount
Once you know a percentage is a fraction over 100, finding it "of" something is easy: you just take that fraction of the amount. 25% of 200 means 25/100 × 200, which is 50. The word "of" is quietly telling you to multiply. Slide the amount in the toy and the answer keeps pace — the percentage stays the same, but "25% of it" changes with the whole.
Why It's Worth Nailing Now
Percentages aren't a school-only thing. Sales, phone plans, interest on savings, the GST on a receipt, a tip at a café — they're all "a number out of 100, applied to an amount". Get this one rung solid and every money problem later is the same move wearing a different hat.