Estimating
is an important part of mathematics and a very handy tool for everyday life.
Get in the habit of estimating amounts of money, lengths of time, distances,
and many other physical quantities.
Rounding
off
is a kind of estimating.
To
round off decimals:
- Find the
place value you want (the "rounding digit") and look at the digit
just to the right of it.
- If that digit
is less than 5, do not change the rounding digit but drop all digits to
the right of it.
- 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:
- Find the
place value you want (the "rounding digit") and look to the digit
just to the right of it.
- 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.
- 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.
Move
your mouse cursor over each digit in the number below to round the number
to that place.