When the calculator is available
The math test has two parts. The first, short part does not allow a calculator. For the rest of the test, an on-screen TI-30XS MultiView scientific calculator is available. The calculator is also available on the Science and Social Studies tests.
Testing centers may allow you to bring your own handheld TI-30XS MultiView. Confirm the current rule when you schedule, since only that model is permitted.
On Science and Social Studies, the calculator is mostly useful for quick work with data: an average from a table, a difference between two values on a graph, or a rate of change. The GED Math No-Calculator Part guide on this site covers how to prepare for the first part of the math test, so this guide focuses on the calculator itself.
Keys worth knowing before test day
The TI-30XS MultiView has many functions, but GED questions rely on a small set. Learn where these keys are and what they do so you are not searching the keypad while the clock runs. GED Testing Service publishes a calculator reference sheet at ged.com that shows how these keys work.
The display shows several lines at once. Use the arrow keys to scroll back to a previous calculation, edit one number, and press enter again instead of retyping the whole thing. That is a fast way to try each answer choice in the same expression.
- The negative key, marked (−), for negative numbers. The subtraction key is only for subtracting.
- The fraction key, marked n/d, to enter a fraction as a stacked numerator and denominator.
- The toggle key, which switches a result between fraction and decimal form.
- The x² key for squaring, and the square root function (2nd, then x²).
- The caret key, marked ^, for powers other than 2.
- The π key for circle and cylinder formulas, so you do not have to round π early.
- The ×10ⁿ key for scientific notation.
- The clear key, to empty the current entry before starting a new problem.
Calculator habits that prevent errors
The calculator follows the order of operations, so it will compute exactly what you type, including your mistakes. Use parentheses generously, especially around negative numbers and around a whole numerator or denominator.
The most common entry mistake is forgetting that a fraction bar or a division acts like a grouping symbol. To average three test scores, the whole sum must be divided, not just the last number. Typing 84 + 91 + 77 ÷ 3 gives about 200.67, because the calculator divides only 77 by 3. Typing (84 + 91 + 77) ÷ 3 gives 84, the correct average. A result that is larger than every number you started with is a clear sign the parentheses are missing.
- Type negative numbers with the negative key, not the subtraction key.
- Put parentheses around a negative number before squaring it.
- Use the fraction key when answer choices are fractions, so you do not have to convert decimals back.
- Estimate first, then check that the calculator result is close to your estimate.
- Clear the screen between problems so an old result does not carry over.
Worked example
Evaluate 18 − 3 × (4 − 6)². Work it by hand, then confirm it on the calculator.
- Parentheses first: 4 − 6 = −2.
- Exponent next: (−2)² = 4.
- Multiply: 3 × 4 = 12.
- Subtract: 18 − 12 = 6.
- On the calculator, type 18 − 3 × (4 − 6) and then x². The result is 6. If you leave out the parentheses and type 18 − 3 × 4 − 6², the calculator correctly computes that different expression and gives −30.
What the formula sheet gives you
The math formula sheet includes formulas for area, perimeter, and circumference, surface area and volume of common solids, the Pythagorean theorem, slope and line equations, and the quadratic formula, among others. GED Testing Service publishes the sheet and a calculator reference guide at ged.com, so you can study with the same pages you will see on test day.
The sheet does not tell you which formula a word problem needs, or which measurement goes where. Practice reading a problem and naming the formula before you look it up. The geometry study guide on this site walks through those choices.
A reliable routine is: name the shape or situation, find the formula, write it on scratch paper, label each letter with a number from the problem, and only then calculate. Watch for measurements that must be changed first. A circle formula uses the radius, but many problems give the diameter. Basic facts that may not appear on the sheet, such as how many inches are in a foot, are worth knowing on your own.
Worked example
A cylindrical water tank has a diameter of 10 feet and a height of 8 feet. To the nearest cubic foot, what is its volume?
- Name the solid and the formula: a cylinder, so V = πr²h from the formula sheet.
- Label the values: the diameter is 10 feet, so the radius is 5 feet. The height is 8 feet.
- Substitute: V = π × 5² × 8 = π × 25 × 8 = 200π.
- Use the π key: 200 × π ≈ 628.32, so the volume is about 628 cubic feet.
- Check the trap: using the diameter as the radius gives π × 100 × 8 ≈ 2,513, four times too large.
Worked example
A ramp rises 5 feet over a horizontal distance of 8 feet. How long is the ramp, to the nearest tenth of a foot?
- Name the formula: the ramp, the rise, and the ground form a right triangle, so use a² + b² = c².
- Substitute: 5² + 8² = c², so 25 + 64 = 89 = c².
- Take the square root with the calculator: √89 ≈ 9.43.
- Round as asked: the ramp is about 9.4 feet long. That is longer than 8 feet, as the slanted side must be.
Practice with the same tools you will use
Familiarity is the real advantage. Download the formula sheet and calculator reference from ged.com and keep them next to you whenever you work on math practice. If you can, practice on a TI-30XS MultiView or an on-screen version of it so the key layout is second nature by test day.
Make a habit of looking up formulas even when you think you remember them. Checking the sheet takes seconds and catches a misremembered formula, such as confusing circumference with area. Save the calculator for messy numbers; arithmetic like 6 × 7 is faster in your head.
Frequently asked questions
- Can I use a calculator on the whole GED math test?
- No. The first part of the math test does not allow a calculator. The rest of the test provides an on-screen TI-30XS MultiView.
- Do I need to memorize math formulas for the GED?
- Most common formulas are on the provided formula sheet. What you need to practice is choosing the right one and using it correctly.
- Can I bring my own calculator?
- Only a TI-30XS MultiView, and only where the testing center permits it. Check when you schedule.
- Why does my calculator give a different answer than I expected?
- Usually a missing set of parentheses or a subtraction key used for a negative number. Group whole numerators, denominators, and negative numbers in parentheses, and compare the result with a quick estimate.