Question

How can I calculate something for example

1/256 & 1/555

Please help

Answer 1

If you need perfect answers, you better be using a calculator, as direct division is time consuming.

For instances where you cannot use a calculator,

To find 1/256, just find 1000/256, which gives approx 3.9. Now, just put decimal point 3 places backward, to eliminate 1000 you multiplied. So you have 0.0039.

For 1/26, just find 100/26=3.85, and then jump 2 decimal places back , so answer is 0.0385.

You can easily approximate answers in such manner.

Eg
to find 1 /256, just find 1000 /250=4. So, 1000/256 will be less than 4, but close. So, 1/256 will be close to 0.004.

1/555 can be found by
1000/550=100/55 is less than 2. So, 1/555 will be less than 0.002. The actual answer is 0.0018, which is very close to predicted answer.

So, you can always make such predictions , and approach a easy solution.

But for problems, its best to keep them as fractions, because in some calculation steps, they will most likely cancel out.