Rounding and estimating

Estimating is an important part of mathematics and a very handy tool for everyday life. It is not always necessary to give the exact number. Get in the habit of estimating amounts of money, lengths of time, distances, and many other physical quantities. For example, if there were 54 785 inhabitants in a town, you could say that its population was approximately 55 000. By doing this, what we have done is to round to the nearest thousand.

Rounding off is a kind of estimating.

To round off decimals:

1. Find the place value you want (the "rounding digit") and look at the digit just to the right of it.
2. If that digit is less than 5, do not change the rounding digit but drop all digits to the right of it.
3. If that digit is greater than or equal to five, add one to the rounding digit and drop all digits to the right of it.

To round off whole numbers:

1. Find the place value you want (the "rounding digit") and look to the digit just to the right of it.
2. If that digit is less than 5, do not change the "rounding digit" but change all digits to the right of the "rounding digit" to zero.
3. If that digit is greater than or equal to 5, add one to the rounding digit and change all digits to the right of the rounding digit to zero.

Depending on the study, we may need to round to the nearest ten, hundred, thousand, ten thousand...

I give you some links to practice here,

Round to the nearest thousand, ten thousand, hundred thousand.