__Significant Digit__ Patterns in Arithmetic:

In *multiplication* and *division*, the number of significant figures in the answer is the least number of significant figures in the calculation (once rounded). For example:

4.56 * 1.4 = 6.38 rounded-> 6.4

4.56 / 1.4 = 3.25 rounded-> 3.3

As the above examples demonstrate, both answers have two significant digits, the least amount in the calculation (1.4 has two significant digits).

In *addition* and *subtraction*, the answer has the same number of decimal places as the least precise measurement used in the calculation (after rounded). For example:

12.11 + 18.0 + 1.013 = 31.123 rounded-> 31.1

18.0 - 12.11 - 1.013 = 4.877 rounded-> 4.9

In both cases, the answer has 1 decimal place, because the least precise measurement, 18.0, only has 1 decimal place.