GED Mathematical Reasoning: How to Use the Built-In Calculator Wisely

The GED Mathematical Reasoning test is 115 minutes long and allows you to use the TI-30XS MultiView calculator — but only for part of the exam. Knowing this detail, and knowing how to use the calculator effectively, can meaningfully improve your score.

How the Calculator Section Works

The GED Math test is split into two sections:

• Section 1 (No Calculator): 5 questions, approximately 15 minutes. You must rely on mental math and pencil-and-paper calculations here.
• Section 2 (Calculator Allowed): Remaining ~40 questions. The on-screen TI-30XS calculator is available.

What the TI-30XS Can Do

The built-in calculator handles most math you'll encounter. Key functions to know:

• Basic arithmetic (add, subtract, multiply, divide)
• Fractions and mixed numbers (the n/d button)
• Exponents and square roots
• Order of operations (automatically applied)
• Negative numbers (use the (-) button, not the minus sign)
• Percentages

Smart Calculator Strategies

1. Set up the problem on paper first. Use the calculator to compute, not to think. Students who go straight to the calculator often make input errors because they haven't organized the problem.
2. Double-check your inputs. It's easy to type 63 instead of 36. After entering a value, glance at the screen to confirm it's right before pressing = .
3. Use the calculator for multi-step problems. Save your mental energy for setting up the logic. Let the calculator handle the arithmetic.
4. Don't use it for simple facts. Calculating 2 × 3 on a calculator wastes time. Mental math for easy operations keeps your pace up.
5. Remember parentheses. For order-of-operations problems, use ( ) to make sure the calculator computes in the right sequence.

Preparing for the No-Calculator Section

The first 5 questions without a calculator typically cover basic arithmetic, fraction operations, and simple percentages. Skills to sharpen:

• Adding and subtracting fractions with different denominators
• Multiplying and dividing fractions (flip and multiply)
• Finding 10%, 25%, and 50% of numbers mentally
• Basic multiplication facts up to 12 × 12

Five minutes of daily mental math practice for two weeks before your exam is enough to feel confident in this section.

The Biggest Calculator Mistake Students Make

Relying on the calculator instead of understanding the concept. If you don't know what to calculate, a calculator won't save you. The GED Math section tests mathematical reasoning — the ability to decide which operations to apply, in which order, to reach the right answer. That thinking has to come from you.