Away to make an approximation to a given number by using fewer digits is called

It is called "rounding"

Step-by-step explanation: Well you can't really explain this one.

Rounding

Step-by-step explanation:

Rounding means to give an approximation of a decimal number. The number may be irrational. Rational numbers have a terminating decimal expansion. When rounding off a number first consider to how many decimals you want to round off the number. Then check the next decimal number if it is 5 or more than 5 then increase the preceding decimal number by 1.

Let us take and example

√2 = 1.41

Round to the nearest tenths

√2 = 1.4

Round 1.65 to the nearest tenths

1.7

1/2 + 1/4 + 1/6 = 3/4 + 1/6 = 11/12 .

1/12 = 1000

1=1000*12

1=12000