|Factor Label||Solids Liquids and gases||Significant Figures| In
math you use numbers, in chemistry we use quantities. A quantity
is described by a number and a unit. 100 is a number : 100 Kg is
a quantity (notice that in chemistry we give meaning to the
numbers). In science we solve a lot of the "math" by watching
the units of the quantities There are two main rules to solving
science problems with the factor-label method: 1. Always carry
along your units with any measurement you use. 2. You need to
form the appropriate labeled ratios (equalities). How many
centimeters in 2 meters? You will see from the metric conversion
chart that 1 meter = 100 cm we turn this into a ratio by writing
it like this: Once you have the equalities you must pick the one
that will cancel out the units leaving the desired units. Then
multiply your starting quantity (2 meters) by the equality that
will give you your desired units. As a rule of thumb your
problem set up should look like this: 1. How many wheels on 350
Ford pickups (u