√984 at a glance
- Exact value
- 2√246
- Decimal (10 places)
- 31.3687742827
- Rounded
- 31.4 · 31.37 · 31.369
- Perfect square?
- No — between 31² and 32²
- Rational?
- Irrational
- Both square roots
- ±31.368774
- Prime factorization
- 2³ × 3 × 41
- Cube root
- 9.946380
How to simplify √984
Look for the largest perfect square that divides 984. Here it is 4 (2²), because 984 = 4 × 246 and 246 has no square factor left:
The prime factorization tells the same story: 984 = 2³ × 3 × 41. Each pair of equal primes leaves the radical as one factor, so 2 comes out and 2 × 3 × 41 stays inside.
Check: (2√246)² = 2² × 246 = 4 × 246 = 984. As a decimal, 2√246 = 2 × 15.6843871414 ≈ 31.3687742827.
Where √984 sits between perfect squares
961 = 31² and 1,024 = 32² are the nearest perfect squares, so √984 lies between 31 and 32. 984 is 23 above 961 and 40 below 1,024, so the root is closer to 31.
- Straight line between 961 and 1,024: 31.3651 (0.01% low)
- Tangent from 31, i.e. 31 + 23 ÷ 62: 31.3710 (0.01% high)
- Tangent from 32, i.e. 32 − 40 ÷ 64: 31.3750 (0.02% high)
For √984 the tangent at 31 wins, missing by only 0.0022. Tangent estimates shine when the number sits close to a perfect square — here 984 is just 23 above 961.
Finding √984 with the Babylonian method
Picture a rectangle with an area of 984 and one side x; the other side must be 984 ÷ x. Averaging the two sides gives a rectangle that is closer to a square, and the side of that square is exactly √984.
Start from the nearest whole number, 31 (31² = 961):
| Step | Guess x | 984 ÷ x | Average | Correct decimals |
|---|---|---|---|---|
| 1 | 31.0000000000 | 31.7419354839 | 31.3709677419 | 2 |
| 2 | 31.3709677419 | 31.3665809769 | 31.3687743594 | 7 |
| 3 | 31.3687743594 | 31.3687742060 | 31.3687742827 | 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 √984 = 31.3687742827 to every decimal shown.
√984 as a continued fraction
Every irrational square root has a continued fraction that repeats. For √984 the pattern is [31; 2, 1, 2, 2, 7, 2, 2, 1, 2, 62] with the block of 10 terms after the semicolon repeating forever. A pattern that never ends is one more proof that √984 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 |
|---|---|---|
| 31/1 | 31.0000000000 | 3.7 × 10⁻¹ |
| 63/2 | 31.5000000000 | 1.3 × 10⁻¹ |
| 94/3 | 31.3333333333 | 3.5 × 10⁻² |
| 251/8 | 31.3750000000 | 6.2 × 10⁻³ |
| 596/19 | 31.3684210526 | 3.5 × 10⁻⁴ |
| 4,423/141 | 31.3687943262 | 2.0 × 10⁻⁵ |
The same fractions solve Pell’s equation, x² − 984y² = 1. Its smallest solution in positive whole numbers is x = 88,805, y = 2,831.
√984 in geometry and everyday measurements
- 984 square feet is 91.4 m². Laid out as a square — a small house footprint or a lot — it is about 31.37 ft (31 ft 4 in) on a side.
- 984 is not a sum of two whole-number squares — the prime factor 3 (one less than a multiple of 4) appears an odd number of times, which rules that out — so √984 is never the diagonal of a rectangle with whole-number sides. It is, however, the space diagonal of a 2 × 14 × 28 box, because 2² + 14² + 28² = 984.
- Since √984 = 2√246, a length of √984 is exactly 2 copies of the length √246 laid end to end.
Square roots near √984 and related roots
| Root | Simplest form | Decimal | Perfect square? |
|---|---|---|---|
| √981 | 3√109 | 31.3209 | No |
| √982 | √982 | 31.3369 | No |
| √983 | √983 | 31.3528 | No |
| √984 | 2√246 | 31.3688 | No |
| √985 | √985 | 31.3847 | No |
| √986 | √986 | 31.4006 | No |
| √987 | √987 | 31.4166 | No |
- The cube root of 984 is about 9.946380.
- Because 984 = 4 × 246, the root is twice √246: 2 × 15.684387 ≈ 31.368774.
Frequently asked questions
What is the square root of 984?
The square root of 984 is 2√246 in simplest radical form, which is about 31.3687742827. The negative root, −31.368774, also squares to 984.
Is the square root of 984 rational or irrational?
Irrational. 984 is not a perfect square — it falls between 961 and 1024 — and the square root of any whole number that is not a perfect square cannot be written as a fraction.
Can √984 be simplified?
Yes. The largest perfect square dividing 984 is 4, so √984 = √4 × √246 = 2√246.
What is √984 rounded to two decimal places?
√984 ≈ 31.37 to two decimal places (31.4 to one, 31.369 to three). Check: 31.37² = 984.0769, close to 984.