Square of 3
3 squared equals 9. 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 9 fits. Between its neighbors, 4 sits 5 below and 16 sits 7 above — the square ladder widens by exactly two at every step. An odd base keeps the square odd: 9 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 |
|---|---|
| 3² | 9 |
Frequently asked questions
What is 3 squared?
3 squared is 9, because 3 × 3 = 9. The exponent 2 is why it is written 3².
What is 4 squared, next to 3²?
4² = 16, which is 7 more than 3² = 9. Each step up adds double the base plus one.
Where do squares show up in real problems?
Area of a square with side 3, distance in the Pythagorean theorem, and variance in statistics all use squared values.