# Question #1c6ee

##### 1 Answer

I would evaluate what is in implicit parentheses first. That means the numerator should be subtracted first, and then the result should be divided.

**ADDITION/SUBTRACTION WITH SIG FIGS**

#4.ul(85)_0 - 2.ul(34)# #"g"#

#=# #2.ul(51)# #"g"#

When you **add/subtract**, you keep the *number of decimal places* given by the number with the greatest uncertainty.

The subscript *drop*, because

**MULTIPLICATION/DIVISION WITH SIG FIGS**

Now, when you **multiply/divide**, you retain the *least number of significant figures* to account for the fact that your volume in *less* significant figures than the mass in

#2.5_1/1.3 "g"/"mL"#

#= 1.9308 => color(blue)("1.9 g/mL"#

The subscript

**NOTE**: *You aren't necessarily less uncertain with more decimal places.*

For example...

#0.00000ul(5)# has only one significant figure, but it has six decimal places.