Posts tagged 'Math'

iPhone App

No more excuses!  A new iPhone app from Quicken connects you with your bank and also let’s you enter your cash purchases.

You know…the money that seems to leave your wallet without your knowing it… and which you can never figure out where it went…

It even tells you what’s left – how much money you have in your account. What, no iPhone? You can still use their simplified version at m.quicken.com.

http://blog.quicken.intuit.com/2009/04/30/introducing-our-first-iphone-app-quicken-online-mobile/

Add comment July 27th, 2009

Interest

There are two kinds of interest: Simple and compound.

Simple interest means that when you borrow money, you pay back the amount you borrowed, which is called the principal, plus the interest. The interest is only calculated on the amount of the principal. The amount of interest you pay back depends on the interest rate, which is usually expressed as a percent due for a full year, and the length of time over which you borrow the money.

There is a formula for calculating simple interest: Simple interest equals: Principal multiplied by the interest rate multiplied by the length of time. While you don’t need to remember the formula, please note two things: (1) The formula only uses multiplication and, (2) You know what each of the things you need to multiply are.

Here is an example of how to calculate simple interest. If you borrowed 1,000 dollars (your principal) at a 10 percent interest rate per year (the bank’s fee), for three years (the time period), the simple interest rate is: 300 dollars (1,000 dollars multiplied by 10 percent interest, multiplied by three years, equals 300 dollars). The total amount you would owe the bank at the end of the three years would be 1,300 dollars (1,000 dollars, the original amount you borrowed, plus the 300 dollars interest).

Compound interest is like simple interest in that when you borrow money, you pay back the amount you borrowed plus the interest. However, unlike with simple interest, where the interest is calculated only once, for compound interest the interest is calculated at the end of each compounding period. A compounding period is how often interest is charged – which can be yearly, monthly, weekly and even daily. This means you are charged interest on the prior period’s interest as well as interest on the principal.

Here is an example of how compound interest is calculated. In the simple interest example above, we borrowed 1,000 dollars at a 10 percent interest rate per year for three years. If the bank charged compound interest instead of simple interest, and they were compounding the interest annually (once a year), we would use the same formula: Interest equals the Principal multiplied by the Interest Rate multiplied by Length of Time, but we would use it three times.

In year one: 1,000 dollars, multiplied by 10 percent, multiplied by one year, equals 100 dollars. The total amount owed at the end of year one would be 1,100 dollars (1,000 dollars, the original amount you borrowed, plus the interest, 100 dollars).

In year two: Perform the calculation again, but this time use as the starting point 1,100 dollars – the balance at the end of year one. To calculate year two, multiply one 1,100 dollars, by 10 percent, by one year. This equals 110 dollars. The total amount owed at the end of year two is 1,210 dollars (1,000 dollars, the original amount you borrowed, plus 100 dollars, the interest from year one, plus 110 dollars, the interest from year two).

In year three, start with the 1,210 dollars from year two and perform the calculation again: 1,210 dollars multiplied by 10 percent, multiplied by one year. The total amount you would owe at the end of year three is 1,331 dollars (1,000 dollars, the original amount you borrowed, plus 100 dollars, the interest from year one, plus 110 dollars, the interest from year two, plus 121 dollars, the interest from year three).

The higher the interest rate, and the more you borrow, the bigger the difference between simple and compound interest becomes. Unfortunately for borrowers and credit card users, the interest on most long-term debts and all credit cards is calculated using compound interest. Banks know how much the difference adds up.

Add comment January 15th, 2009

Economic Recovery

Today, Obama spoke about the current economic crises. He pointed out that “this crisis did not happen solely by some accident of history or normal turn of the business cycle … we arrived at this point due to an era of profound irresponsibility that stretched from corporate boardrooms to the halls of power in Washington, DC. … Banks made loans without concern for whether borrowers could repay them, and some borrowers took advantage of cheap credit to take on debt they couldn’t afford. The result has been a devastating loss of trust and confidence in our economy, our financial markets, and our government.” He’s right.

The recent economic headlines have been enough to make anyone nauseous. Money-savvy people are scared and financial novices are terrified. One of the most important promises you can make to yourself this year is to learn about money and personal money management. I realize learning about the economy can seem intimidating, math feels boring, and managing your own finances daunting – but if you can shop, you can manage your money.

Shopping actually requires you know more math than money management. For example to spend, you need addition and subtraction. To budget, you need addition, subtraction, and multiplication. To over-spend, you need addition, subtraction, multiplication and division. To shop, you need addition, subtraction and multiplication. Percents and decimals also help – especially if there is a sale! Notice that algebra is not listed; geometry is nowhere is sight (although one way to save money is to angle around the outer perimeters of the shoe department); trigonometry – forget it; calculus – don’t need it.

So make a commitment to yourself and learn about money. You’ll feel even better than you do when your skinny jeans fit.

2 comments January 8th, 2009