Approximate decimal places

The key is to grasp how many decimal places to keep, which can be summarized as follows. If you want to keep n decimal places, look at the value of (n+ 1). If it is less than four, you can add 1 to five decimal places to get an approximate value.

Examples are as follows:

One,

3.15,4.12 If one decimal place is to be reserved, the former is 3.2 and the latter is 4.1;

Second,

4. 153,5.127 If two decimal places are reserved, the former is 4.15 and the latter is 5. 13.