Start from zero — the basic math you need before everything else
A fraction shows part of a whole. The bottom number, the denominator, tells you how many equal pieces the whole is cut into. The top number, the numerator, tells you how many of those pieces you take. So 3/4 means: cut into 4 equal pieces, take 3 of them.
Different-looking fractions can be the same amount. Multiply or divide both top and bottom by the same number and the value doesn't change: 1/2 = 2/4 = 3/6. Dividing top and bottom to make the numbers smaller is called simplifying, which writes a fraction in its smallest terms.
A pizza makes fractions obvious. Cut it into 4 equal slices and the bottom number (the denominator) is 4. Eat 3 slices and the top number (the numerator) is 3: you've eaten 3/4 of the pizza. Cut the same pizza into 8 and eat 6 — that's 6/8, the very same amount, just smaller slices.
▶ What a Fraction Is