The calculator, better known as the "**calc**" has been an integral component of Windows since 1989 when windows version 3.0 was introduced. A lot has changed in Windows over the years, but apart from the look and feel, the good old calculator has remained almost the same.

Now can you imagine a bug that existed in the calculator since it was first introduced and was never fixed by the Microsoft guys? Oh yes, there is a bug and a very stupid one indeed.

Here's how you can see it - Just try to subtract 2 from the square root of 4.

sqrt(4)-2

Square root of 4 is 2 and "2-2" should give 0. But here's the surprise - our calculator would give a small negative number as the result instead of 0. In "**Standard**" mode, you would see the result "**-1.068281969439142e-19** " and in the "Scientific" mode, the result would be "**-8.1648465955514287168521180122928e-39**".

In fact, you can reproduce the error with any similar calculation like "**sqrt(9)-3**" or "**sqrt(16)-4**" and so on. Here's a video of the bug in action -

The real reason for the bug is the way calculator handles **sqrt **operations. The results are stored as floating point numbers instead of integers and the small precision error when it comes to floating point calculations is what you see.

It is definitely a bug which either the super intelligent Microsoft techies never found or simply didn't bother to fix. Never the less, I am sure you will ask yourself "**Should I double check**" the next time you use the calculator :)

**Related**: Did you know your windows calculator could do these?