Square of 15
15 squared equals 225. 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 — 0 here. On the last digit, squares end only in 0, 1, 4, 5, 6 or 9, and 5 fits. Between its neighbors, 196 sits 29 below and 256 sits 31 above — the square ladder widens by exactly two at every step. An odd base keeps the square odd: 225 ends in an odd digit, as every odd square must. 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 |
|---|---|
| 15² | 225 |
Frequently asked questions
What is 15 squared?
15 squared is 225, because 15 × 15 = 225. The exponent 2 is why it is written 15².
What is 16 squared, next to 15²?
16² = 256, which is 31 more than 15² = 225. Each step up adds double the base plus one.
Where do squares show up in real problems?
Area of a square with side 15, distance in the Pythagorean theorem, and variance in statistics all use squared values.