√106 at a glance
- Exact value
- √106
- Decimal (10 places)
- 10.2956301410
- Rounded
- 10.3 · 10.30 · 10.296
- Perfect square?
- No — between 10² and 11²
- Rational?
- Irrational
- Both square roots
- ±10.295630
- Prime factorization
- 2 × 53
- Cube root
- 4.732623
How to simplify √106
The prime factorization of 106 is 2 × 53. Every prime appears only once, so there is no pair to bring outside the radical — √106 is already in simplest form (a "square-free" radicand).
A whole number has a rational square root only when every prime in its factorization appears an even number of times. In 106, 2 and 53 appear an odd number of times, so √106 is irrational and 10.2956301410 is a rounded value.
Where √106 sits between perfect squares
100 = 10² and 121 = 11² are the nearest perfect squares, so √106 lies between 10 and 11. 106 is 6 above 100 and 15 below 121, so the root is closer to 10.
- Straight line between 100 and 121: 10.2857 (0.1% low)
- Tangent from 10, i.e. 10 + 6 ÷ 20: 10.3000 (0.04% high)
- Tangent from 11, i.e. 11 − 15 ÷ 22: 10.3182 (0.22% high)
For √106 the tangent at 10 wins, missing by only 0.0044. Tangent estimates shine when the number sits close to a perfect square — here 106 is just 6 above 100.
Finding √106 with the Babylonian method
The idea is ancient. A Babylonian clay tablet catalogued as YBC 7289, about 3,800 years old, records √2 correct to roughly six decimal places, and Heron of Alexandria described this averaging rule in the first century AD.
Start from the nearest whole number, 10 (10² = 100):
| Step | Guess x | 106 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 10.0000000000 | 10.6000000000 | 10.3000000000 | 2 |
| 2 | 10.3000000000 | 10.2912621359 | 10.2956310680 | 6 |
| 3 | 10.2956310680 | 10.2956292140 | 10.2956301410 | all 10 shown |
The count of correct decimals went 2, 6 and all 10 over 3 steps — roughly doubling each time — until the guess matched √106 = 10.2956301410 to every decimal shown.
√106 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √106 the pattern is [10; 3, 2, 1, 1, 1, 1, 2, 3, 20] with the block of 9 terms after the semicolon repeating forever. A pattern that never ends is one more proof that √106 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 |
|---|---|---|
| 10/1 | 10.0000000000 | 3.0 × 10⁻¹ |
| 31/3 | 10.3333333333 | 3.8 × 10⁻² |
| 72/7 | 10.2857142857 | 9.9 × 10⁻³ |
| 103/10 | 10.3000000000 | 4.4 × 10⁻³ |
| 175/17 | 10.2941176471 | 1.5 × 10⁻³ |
| 278/27 | 10.2962962963 | 6.7 × 10⁻⁴ |
The same fractions solve Pell’s equation, x² − 106y² = 1. Its smallest solution in positive whole numbers is x = 32,080,051, y = 3,115,890. Because the period is odd, the equation with −1 on the right also has a solution: 4,005² − 106 × 389² = −1.
√106 in geometry and everyday measurements
- A square room or garden bed covering 106 square feet measures about 10.3 ft (10 ft 4 in) along each wall.
- 106 = 5² + 9², so by the Pythagorean theorem √106 is the diagonal of a 5 × 9 rectangle — and the distance between the points (0, 0) and (5, 9) on a grid.
Square roots near √106 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √103 | √103 | 10.1489 | No |
| √104 | 2√26 | 10.1980 | No |
| √105 | √105 | 10.2470 | No |
| √106 | √106 | 10.2956 | No |
| √107 | √107 | 10.3441 | No |
| √108 | 6√3 | 10.3923 | No |
| √109 | √109 | 10.4403 | No |
- The cube root of 106 is about 4.732623.
- Four times the radicand doubles the root: √424 = 2 × √106 ≈ 20.59126.
Frequently asked questions
What is the square root of 106?
The square root of 106 is √106, about 10.2956301410. The negative root, −10.295630, also squares to 106.
Is the square root of 106 rational or irrational?
Irrational. 106 is not a perfect square — it falls between 100 and 121 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √106 be simplified?
No. 106 = 2 × 53 has no repeated prime factor, so there is no perfect square to take out of the radical.
What is √106 rounded to two decimal places?
√106 ≈ 10.30 to two decimal places (10.3 to one, 10.296 to three). Check: 10.30² = 106.09, close to 106.