Whether you're buying calculators for personal use, trying to pick the right calculator for your child's education or want a handy device to help you crunch numbers, it's helpful to understand the various calculator designs so you can choose the model that best suits your needs.

>> How will you use a calculator?

When you're choosing which calculator to buy, the first consideration is twofold; where you use it and what type of math problems you need to solve. While there is a great deal of cross-functionality among calculators, certain styles are best suited to specific purposes.

>> Do you need a calculator while you're on the go?

If you're looking for a calculator to keep in your purse or pocket, then you'll probably enjoy a pocket or handheld calculator. Another take on this calculator design is a folding calculator, which has a case to protect the keys and display. Basic calculators that clip onto notebook rings are also handy for people on the go.

>> Thinking about calculators for school

By far the biggest selection of calculators is for those in school. It's likely that children will own several different types of calculators as they progress in their education:

• Children in grade school probably need just a standard calculator that calculates basic arithmetic.

• As a child moves into junior high school, they might need a scientific calculator to handle more complex computations, like those in geometry.

• For those children who take courses that use advanced math in high school and college, like those in chemistry, algebra, calculus, physics and engineering, a graphing calculator will probably be the best calculator to buy.

>> Do you need a scientific calculator?

When deciding which calculator to buy, consider a scientific calculator if you need a tool that performs more complex operations than a simple calculator does, but you don't need graphing capabilities. This type of calculator performs a broad range of calculations to solve problems in classes such as physics and trigonometry as well as exponential calculations, just to name a few. For middle school students, as well as professionals such as architects, designers and engineers, a scientific model might be the best calculator to buy.

>> Do you need a graphing calculator?

Graphing calculators are the most advanced type of calculators on the retail market. For the most part, schools from middle school to universities require students to use graphing calculators for advanced math classes. Once a student enters algebra, a school might request or require this advanced calculator design.

Before you shop for calculators, be sure to find out if the curriculum requires a specific make and model. Certain calculator designs might be required because students will share data with classmates and upload to computers while in the classroom. When a teacher suggests a specific model, it's usually best to go with the recommendation.

Uses for graphing calculators extend from basic geometry calculators to advanced calculus. As the name implies, the screen displays graphs as well as numbers. Most models can connect to a computer through a USB connection. Highly advanced models come with color screens and the ability to perform extremely complex calculations.

Though one brand dominates the market, there is a wide selection of graphing calculators for you to consider as you choose which calculator to buy. If you're interested in buying a less prominent brand, check with your school and teachers to make sure your preference is acceptable.

>> Do you need a financial calculator?

As you decide which calculator to buy, you might come across a special designation of scientific calculators called financial calculators. What makes them different from standard scientific calculators is that they are pre-programmed with financial formulas such as compound interest, return on investment and time value of money.

If you're buying a calculator for studies in finance or business, this might be the best calculator to buy. People who work in financial consulting will also appreciate a tool that makes quick work of common business-related calculations.

>> Do you need a calculator for work?

Financial calculators and desktop calculators are popular in the workplace. Some models include the option to print calculations on a paper roll, similar to receipt paper. These are the best calculators to buy if you need a paper trail or regularly perform audits. In general, these calculators feature an angled display, large characters and large buttons.

>> Consider power sources As you determine which calculator to buy, you might decide that one type of power is a better fit for you than another. Battery-powered: Graphing calculators and some desktop calculators use standard batteries. Graphing calculators often require four AA batteries, while printing desktop calculators might offer a battery as an alternative to electric power.

Solar-powered: Basic, scientific and financial calculators are often solar-powered. While this calculator design does often have a small internal battery, its primary power is ambient light. With no batteries to change, you won't run out of power in mid-calculation. If the calculator includes a built-in battery, then the solar panel will also charge the battery, so that you can calculate in a variety of lighting conditions.

Electric-powered: Wall current often powers desktop calculators. Some advanced graphing calculators might also include an AC adapter. These types of calculators are most popular with accountants and bookkeepers.

>> Consider display size

A final consideration as you pick which calculator to buy is display size. Regardless of whether the calculator is a basic folding calculator design or an advanced graphing calculator, most measure screen size in lines and characters. In general, the more lines displayed, the more advanced the calculator is. Another consideration with display is the size of the characters. Desktop calculators usually have the largest characters, while graphing calculators are usually smallest. It's helpful to consider display size and quality as you choose your new calculator.

The calculator comparison chart below summarizes the basic features of different types of calculators.

Typical user(s) Use(s) Power source(s) Typical display size(s) Advantage(s) Basic Everyone Basic arithmetic Solar 1 line, 8-12 digits Lightweight, convenient Desktop Office settings Basic arithmetic, limited business functions Solar/electric 1 line, 8-12 digits Might print calculations, large display Scientific Students, scientists Advanced math Solar/battery 1-4 lines, 8-16 digits Performs complex functions in a lightweight design Financial Students, financial consultants Business and money centered calculations Solar/battery 1-4 lines, 8-16 digits Makes depreciation, bonds, markups and other business calculations with ease Graphing Students Learning and solving complex math problems Battery 8 + lines, 14+ characters Valuable tool for learning math >