Square of 28
28 squared equals 784. Squares appear in area calculations, the Pythagorean theorem, and statistics (variance uses squared distances).
Squares obey quiet rules. Divided by 9, a square only ever leaves 0, 1, 4 or 7 — 1 here. On the last digit, squares end only in 0, 1, 4, 5, 6 or 9, and 4 fits. Between its neighbors, 729 sits 55 below and 841 sits 57 above — the square ladder widens by exactly two at every step. Double the base and the square quadruples: 56² = 3136, which is 4 × 784. Two anchors most worth memorizing in this range are 12² = 144 and 15² = 225 — the odd-step rule above is why knowing them pays off, because from any anchor the next square is one step along this page's ladder.
| Expression | Value |
|---|---|
| 28² | 784 |
Frequently asked questions
What is 28 squared?
28 squared is 784, because 28 × 28 = 784. The exponent 2 is why it is written 28².
What is 29 squared, next to 28²?
29² = 841, which is 57 more than 28² = 784. Each step up adds double the base plus one.
Where do squares show up in real problems?
Area of a square with side 28, distance in the Pythagorean theorem, and variance in statistics all use squared values.