Example: Adding and Subtracting with Significant Figures
A step in your Let us Make a Latte chemistry lab assignment requires that you account for the volume of fluids in your latte.You are starting with 7 oz. of milk, and your espresso machine uses 2.5 oz. of water to make a 2 oz. espresso shot -- the other 0.5 oz. remains in the espresso puck. Finally, your high tech milk steamer tells you how much water is used in the steaming process, out to 3 decimal places.
You make your espresso and see that you have pulled the perfect 2 oz. shot. You steam and froth your milk, and the steamer indicator says 0.063 oz. of water was used during the process. You need to add up 2 oz. espresso plus 7 oz. milk plus 0.063 oz. of steam. But because this is a chemistry lab assignment you have to do your math with significant figures..