GCSE Calculator Skills

How It Works

1. Watch it. The calculator presses every key itself. Each key glows just before it is pressed and the screen changes exactly as the real one does. Pause, step back or slow it down.
2. Your turn. Same question, and now you press the keys. Every press is checked before it reaches the calculator. Press the wrong one and it tells you which key you pressed and which one you need.
3. Three in a row. Two more questions with new numbers, and the skill is done. Your progress stays on this device.

The Skills

• Prime factors with FACT. Write a number as a product of primes in one press.
• HCF and LCM. No HCF key on the fx-83GTX. Make a fraction and let it simplify.
• Decimal answers with S⇔D. Your answer came out as a fraction. Turn it into a decimal.
• Recurring decimals. Turn a recurring decimal into a fraction to check your algebra.
• Hours and minutes with °′″. 3.7 hours is not 3 h 70 min. Let the calculator convert it.
• Standard form. Type powers of 10 with the ×10ˣ key, never × 10 ^.
• Trig: find an angle. SHIFT then sin, cos or tan gives the angle.
• Iteration with Ans. x₁, x₂, x₃ in three presses of =.
• Check a quadratic root. Store the root in x, type the quadratic, look for 0.
• Table of values. MENU 3 fills in a table of values for a graph, and shows where it crosses 0.
• Mean from a frequency table. Type the table into Statistics mode and read off the mean.
• Ratio: find the missing number. MENU 4 solves A : B = X : D for you.

The fx-83GTX has no HCF, LCM or equation solver key, so these are the methods that work on the calculator you actually take into the exam. For free practice with every key, open the scientific calculator.