Percentage Changes
Percentage changes show you how much more or less something is worth this year than last year—how much money you've made in your 401(k), for example, or how much you've earned on your house. Often, when you deal with brokerage firms and read the stock pages, the percentage changes are computed for you. But knowing how to do it yourself can be helpful—and it's easy.

Figuring out a percentage change is a two-step process.

1. Take today's value and subtract the prior value from it.
2. Divide that answer by the prior value.

Suppose the following: Your house is worth $300,000 now, you bought it for $220,000, and you want to know how much money you made in percentage terms.

1. First, subtract the prior value from today's value:
   $300,000 – $220,000 = $80,000.
2. Then divide that answer by the prior value:
   $80,000 / $220,000 = .363636.
   You made slightly over 36 percent. In other words, you made a killing.

Map to a Million
Make a simple math move that's guaranteed to improve your financial situation.

Move $2,000 a year from a savings account earning 1.5 percent to a money market account earning 4 percent.

	1.5%	4%	EARNINGS DIFFERENCE
10 years	$23,738	$27,076	$3,338
20 years	$48,993	$64,461	$15,468
30 years	$78,332	$120,196	$41,864

Move $2,000 a year from a savings account earning 1.5 percent to an index fund earning 8 percent. 

	1.5%	4%	EARNINGS DIFFERENCE
10 years	$23,738	$33,828	$10,090
20 years	$48,993	$104,475	$55,482
30 years	$78,332	$261,288	$182,956

Math 101 continues...