√916 at a glance
- Exact value
- 2√229
- Decimal (10 places)
- 30.2654919008
- Rounded
- 30.3 · 30.27 · 30.265
- Perfect square?
- No — between 30² and 31²
- Rational?
- Irrational
- Both square roots
- ±30.265492
- Prime factorization
- 2² × 229
- Cube root
- 9.711772
How to simplify √916
Look for the largest perfect square that divides 916. Here it is 4 (2²), because 916 = 4 × 229 and 229 has no square factor left:
The prime factorization tells the same story: 916 = 2² × 229. Each pair of equal primes leaves the radical as one factor, so 2 comes out and 229 stays inside.
Check: (2√229)² = 2² × 229 = 4 × 229 = 916. As a decimal, 2√229 = 2 × 15.1327459504 ≈ 30.2654919008.
Where √916 sits between perfect squares
900 = 30² and 961 = 31² are the nearest perfect squares, so √916 lies between 30 and 31. 916 is 16 above 900 and 45 below 961, so the root is closer to 30.
- Straight line between 900 and 961: 30.2623 (0.01% low)
- Tangent from 30, i.e. 30 + 16 ÷ 60: 30.2667 (0% high)
- Tangent from 31, i.e. 31 − 45 ÷ 62: 30.2742 (0.03% high)
For √916 the tangent at 30 wins, missing by only 0.0012. Tangent estimates shine when the number sits close to a perfect square — here 916 is just 16 above 900.
Finding √916 with the Babylonian method
Picture a rectangle with an area of 916 and one side x; the other side must be 916 ÷ x. Averaging the two sides gives a rectangle that is closer to a square, and the side of that square is exactly √916.
Start from the nearest whole number, 30 (30² = 900):
| Step | Guess x | 916 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 30.0000000000 | 30.5333333333 | 30.2666666667 | 2 |
| 2 | 30.2666666667 | 30.2643171806 | 30.2654919236 | 7 |
| 3 | 30.2654919236 | 30.2654918780 | 30.2654919008 | all 10 shown |
The count of correct decimals went 2, 7 and all 10 over 3 steps — roughly doubling each time — until the guess matched √916 = 30.2654919008 to every decimal shown.
√916 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √916 the pattern is [30; 3, 1, 3, 3, 1, 1, 14, 1, 1, 3, 3, 1, …] with the block of 14 terms after the semicolon repeating forever (only the first 12 of the 14 are shown). A pattern that never ends is one more proof that √916 is irrational.
Cutting the continued fraction off early gives the best fractions for approximating the root — no fraction with a smaller denominator comes closer:
| Fraction | Decimal | Error |
|---|---|---|
| 30/1 | 30.0000000000 | 2.7 × 10⁻¹ |
| 91/3 | 30.3333333333 | 6.8 × 10⁻² |
| 121/4 | 30.2500000000 | 1.5 × 10⁻² |
| 454/15 | 30.2666666667 | 1.2 × 10⁻³ |
| 1,483/49 | 30.2653061224 | 1.9 × 10⁻⁴ |
| 1,937/64 | 30.2656250000 | 1.3 × 10⁻⁴ |
The same fractions solve Pell’s equation, x² − 916y² = 1. Its smallest solution in positive whole numbers is x = 5,848,201, y = 193,230.
√916 in geometry and everyday measurements
- 916 square feet is 85.1 m². Laid out as a square — a small house footprint or a lot — it is about 30.27 ft (30 ft 3 in) on a side.
- 916 = 4² + 30², so by the Pythagorean theorem √916 is the diagonal of a 4 × 30 rectangle — and the distance between the points (0, 0) and (4, 30) on a grid.
- Since √916 = 2√229, a length of √916 is exactly 2 copies of the length √229 laid end to end.
Square roots near √916 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √913 | √913 | 30.2159 | No |
| √914 | √914 | 30.2324 | No |
| √915 | √915 | 30.2490 | No |
| √916 | 2√229 | 30.2655 | No |
| √917 | √917 | 30.2820 | No |
| √918 | 3√102 | 30.2985 | No |
| √919 | √919 | 30.3150 | No |
- The cube root of 916 is about 9.711772.
- Because 916 = 4 × 229, the root is twice √229: 2 × 15.132746 ≈ 30.265492.
Frequently asked questions
What is the square root of 916?
The square root of 916 is 2√229 in simplest radical form, which is about 30.2654919008. The negative root, −30.265492, also squares to 916.
Is the square root of 916 rational or irrational?
Irrational. 916 is not a perfect square — it falls between 900 and 961 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √916 be simplified?
Yes. The largest perfect square dividing 916 is 4, so √916 = √4 × √229 = 2√229.
What is √916 rounded to two decimal places?
√916 ≈ 30.27 to two decimal places (30.3 to one, 30.265 to three). Check: 30.27² = 916.2729, close to 916.