Quick Reference Table
Number | (approx.) | Rational or Irrational |
|---|---|---|
121 | 11 | Rational |
144 | 12 | Rational |
146 | 12.083 | Irrational |
150 | 12.247 | Irrational |
153 | 12.369 | Irrational |
157 | 12.530 | Irrational |
169 | 13 | Rational |
Where Does √146 Appear?
is the length of the diagonal of a rectangle, because , so the Pythagorean theorem gives a diagonal of . It also shows up whenever a distance calculation lands on a sum of squares that equals 146, such as the gap between the grid points and on a coordinate plane.
What Is A Square Root?
A square root of a number is a value such that . So the square root of 146 is the number that, multiplied by itself, gives 146.
No whole number does this: is too small and is too big. So lands between 12 and 13, much closer to 12.
Is The Square Root Of 146 Rational Or Irrational?
is irrational - it cannot be written as a fraction of two integers, and its decimal never terminates or repeats.
Here is the quick reason. A whole number has a rational square root only when it is a perfect square, and 146 sits strictly between the perfect squares and .
The prime factorisation confirms it: . Both primes appear to an odd power, so no factor can be pulled out as a whole number, which is exactly what marks an irrational number. The same test explains every entry in the square root 1 to 30 reference list.
How Do You Find √146? (Long Division Method)
The long-division method builds the decimal one digit at a time. It is the same idea as long division with numbers, applied to a square root.
Step 1: Pair the digits around the decimal point.
Step 2: The largest number whose square is at most 1 is 1.
Step 3: Subtract and bring down the next pair.
Step 4: Double the quotient (1) to get 2, then find a digit with .
Step 5: The quotient is now 12, remainder 2.
Step 6: Bring down a pair of zeros and continue.
After three decimal places, . The process never ends, which is what makes the value irrational.
Examples Of √146
Example 1
Estimate to the nearest tenth without a calculator.
Find the two perfect squares around 146.
146 is only 2 above 144, so the root is just above 12.
Example 2
A student writes . Where does this break?
Watch the wrong path first. Splitting a square root across addition treats as .
Test it against a known value.
If the split were valid, would be about 16.78, larger than . That is impossible, since 146 is less than 169.
The correct rule: square roots do not distribute over addition. Only holds, so stays as .
Example 3
Simplify into simplest radical form.
Factor 146 into primes.
Neither prime repeats, so there is no perfect-square factor to pull out.
The answer is already in simplest radical form - the same simplifying radical expressions rule that turns into simply finds nothing to pull out here.
Example 4
Find the value of .
Squaring undoes the square root.
The answer is exactly 146, with no rounding.
Example 5
A square patch of land has an area of 146 square metres. What is the side length?
The side of a square equals the square root of its area.
So each side is about 12.08 metres.
Common Mistakes
Mistake 1: Splitting the root across addition
Where it slips in: Trying to shortcut using nearby round numbers.
Don't do this: Writing .
The correct way: Roots split only over multiplication, so keep whole or estimate it directly.
Mistake 2: Claiming √146 can be simplified
Where it slips in: Assuming every root reduces to something like .
Don't do this: Writing and calling it simpler.
The correct way: Since has no repeated prime, is already simplest — the many learners who expect a clean radical here are the ones who stall.
Mistake 3: Rounding too early
Where it slips in: Multi-step problems that use before the final line.
Don't do this: Replacing with 12.08 at the start and carrying that through.
The correct way: Keep the radical symbolic until the last step, then round once.
Conclusion
The square root of 146 is about 12.083 and is irrational.
, so has no simpler radical form.
Long division gives the decimal digit by digit: .
Roots split over multiplication, never over addition — the trap in Example 2.
To go further with a teacher, explore Bhanzu's algebra tutor sessions, a high school math tutor, or live math classes online. Want to see the method taught live? Book a free demo class.
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