 Welcome to this learning object, chemistry math, solving a formula. In chemistry, we use mathematical expressions to show how real physical phenomena are related. For instance, d equals m divided by v says that the mass of a substance divided by its volume is the density of the substance. We use the tools of simple algebra to manipulate the symbols and quantities found in such expressions. This lets us rearrange the formula and solve for whatever term we want. The term you want to find has to be all by itself on one side of the equal sign with everything else on the other side. It doesn't matter on which side you show the unknown term. Density equals mass divided by volume is the same as mass divided by volume equals density. You may add, subtract, multiply or divide to remove other terms. The key principle is that whatever you do to one side of the equation you must do to the other side as well. What if you want to solve the density formula for m? Mass. You have to get m all by itself. To remove a term that's below a dividing line, you multiply both sides by that term. So remove the v term by multiplying each side by v. On the right, v divided by itself equals 1, so they cancel each other out. The formula is now solved for m. Mass equals volume times density. To remove a term that's multiplying another one, you divide both sides by that multiplier. In the equation, v times d equals m. To solve for v, you divide both sides by d. Now solve this formula for n. p times v equals n times r times t. Now for the addition and subtraction. To remove an added term, you subtract it from both sides. Solve for degrees Celsius in the equation k equals degrees Celsius plus 273. Remember, this is the same as degrees Celsius equals k minus 273. To remove a subtracted term, add it to both sides. Solve for k in the equation k minus 273 equals degrees Celsius. Now combine the rules to solve this temperature conversion formula for degrees Celsius. Degrees Fahrenheit equals 1.8 times degrees Celsius plus 32. Rule, remove the most distant terms first. In this case, the added term plus 32 is farther away from the degrees Celsius, so remove it first. Now remove the multiplier. Degrees Celsius equals degrees Fahrenheit minus 32 divided by 1.8. In order to check our final answer, let's try our last example in reverse. Solve for degrees Fahrenheit. What is the most distant term this time? In this case, it is the 1.8 dividing term because it applies to degrees Fahrenheit minus 32 as a group. 1.8 degrees Celsius plus 32 equals degrees Fahrenheit. Congratulations! You have completed this learning object, Chemistry Math, Solving a Formula.