How to make a table of values on a Casio ClassWiz or fx-CG50
On the fx-991EX: MENU → 9 (Table).On the fx-991CW: HOME → Table.
Fill in "complete the table" questions in seconds and spot sign changes for roots. Exact keystrokes for the Casio ClassWiz first (the fx-991EX and fx-991CW have different menus, so each has its own tab), then the graphic calculators, a worked example you can check your answers against, the mistakes that cost marks, and the same thing in Desmos.
When you need it
Every "complete the table of values, then draw the graph of y = …" question. The table function fills it in exactly; then plot the points carefully.
Practise it: IGCSE units (Unit 3: Graphs).
Keystrokes on your calculator
Pick your calculator: the page remembers it next time.
Tables of values on the Casio fx-991EX ClassWiz
Written for the fixed ROM (these models take no OS updates). Casio fx-991EX ClassWiz: scientific (no graphs).
Watch the key presses on the fx-991EX9 presses, one at a time
The walkthrough needs JavaScript. The same key presses are in the numbered steps below.
- MENU 9 (Table).
- Type f(x) = X² − 3X + 1 and press =. If a g(x) line appears, press = again to leave it empty (whether g(x) is offered is a Table setting in SHIFT MENU (SETUP)).
- Start −1 =, End 4 =, Step 0.5 =. The table appears.
- With both f(x) and g(x) the table holds up to 30 rows; with f(x) only, 45.
Tables of values on the Casio fx-991CW ClassWiz
Written for the fixed ROM (these models take no OS updates). Casio fx-991CW ClassWiz: scientific (no graphs); the newer ClassWiz with a HOME menu of apps.
- HOME → Table.
- Define f(x) = X² − 3X + 1 (Define f(x)/g(x) in the app's menu), then Table Range: Start −1, End 4, Step 0.5, and EXE.
- Show the table and scroll with the arrow keys. Table Type chooses f(x) only, g(x) only or both.
- The table holds up to 45 rows with f(x) or g(x) only, and 30 with both (the default is both).
Tables of values on the Casio fx-CG50
Written for OS 3.80 (menus unchanged from OS 3.60 onwards as far as we can tell). Casio fx-CG50: graphic (GDC).
- MENU 7 (TABLE).
- Type Y1 = X² − 3X + 1 and EXE.
- F5 (SET): Start −1 EXE, End 4 EXE, Step 0.5 EXE, then EXIT.
- F6 (TABLE). Scroll with ▼. Change any X value in the table to see y there.
- Two functions (Y1, Y2) give two columns: handy for comparing a model with data or for f(x) and g(x).
Tables of values on the TI-84 Plus CE
Written for OS 5.8.x. TI-84 Plus CE: graphic (GDC); also the TI-84 Plus CE Python / CE-T Python Edition.
- y=: Y1 = X² − 3X + 1.
- 2nd window (TBLSET): TblStart = −1, ΔTbl = 0.5, Indpnt: Auto.
- 2nd graph (TABLE). Scroll with the arrow keys.
- Set Indpnt: Ask to type in your own x values (useful for uneven tables).
Tables of values on the TI-Nspire CX II
Written for OS 6.x. TI-Nspire CX II: graphic (GDC), non-CAS (the CX II CAS is a different model: check the exam rules before using one).
- Graphs page: f1(x) = x² − 3x + 1.
- ctrl T shows the table next to the graph.
- menu → Table → Edit Table Settings: Table Start −1, Table Step 0.5.
For teachers: Show on the board Print a keystroke card Teaching GDC skills
Worked example
Complete a table of y = x² − 3x + 1 for x = −1 to 4 in steps of 0.5, and find two intervals that contain a root.
Answers (checked with Python)
For example f(0) = 1, f(0.5) = −0.25, f(2.5) = −0.25, f(3) = 1. The sign changes between 0 and 0.5 and between 2.5 and 3, so there are roots in [0, 0.5] and [2.5, 3] (they are x ≈ 0.382 and 2.618).
Now try it on an exam-style question
Use the keystrokes above on IGCSE-style quadratic and cubic graphs questions. Free to try, no sign-up.
Common calculator mistakes
- Squaring negatives: typing −1² gives −1. The table uses X² correctly, but when you check a value by hand, bracket it: (−1)².
- Step too large: a step of 1 can jump straight over two roots close together.
- A sign change shows a root only if the function is continuous there: y = 1/x changes sign at 0 with no root.
- Plot points from the table accurately and join them with a smooth curve, not straight lines.
If you get an error
fx-991EX: Math ERROR, Syntax ERROR
Math ERROR A result, or a value you typed, is outside the range the calculator can handle, or you asked for something mathematically impossible, such as dividing by zero. Check: Look for a zero denominator, sin⁻¹ or cos⁻¹ of a number bigger than 1 (often a wrong side or angle in the sine or cosine rule), the log of 0 or of a negative number, and a value stored in a variable earlier that you forgot about. Fix: Casio's advice: check the values you typed, use fewer digits and try again. If a variable is the input to a function, make sure its value is one the function accepts.
Syntax ERROR There is a problem with the format of the calculation. In Matrix and Vector calculations it also appears when the sizes do not suit the operation. Check: A missing or extra bracket, or two operation signs in a row. With matrices or vectors: adding a 2 × 2 to a 3 × 3, or a product whose sizes do not match. Fix: Casio's advice: make the corrections. For matrices and vectors, check the size you set for each one.
fx-991CW: Math ERROR, Syntax ERROR
Math ERROR A result, or a value you typed, is outside the range the calculator can handle, or you asked for something mathematically impossible, such as dividing by zero. Check: Look for a zero denominator, sin⁻¹ or cos⁻¹ of a number bigger than 1 (often a wrong side or angle in the sine or cosine rule), the log of 0 or of a negative number, and a value stored in a variable earlier that you forgot about. Fix: Casio's advice: check the values you typed, use fewer digits and try again. If a variable is the input to a function, make sure its value is one the function accepts.
Syntax ERROR There is a problem with the format of the calculation: it is typed in a form the calculator cannot read. Check: A missing or extra bracket, two operation signs in a row, or a function with nothing after it. Fix: Casio's advice: make the corrections and try again.
fx-CG50: Ma ERROR
Ma ERROR Casio's Math ERROR: the result is outside the allowable calculation range, or you are trying to do an illegal mathematical operation, such as dividing by zero. Check: Look for a zero denominator, sin⁻¹ or cos⁻¹ of a number bigger than 1 (often a wrong side or angle in the sine or cosine rule), the log of 0 or of a negative number, and a value stored in a variable earlier that you forgot about. Fix: Casio's advice: check your input values and change them so the result is within the allowable range.
TI-84 Plus CE: ERR:DOMAIN, ERR:INVALID DIM, ERR:SYNTAX
ERR:DOMAIN A value given to a function or instruction is outside the values it accepts. In a regression, TI says it means the data do not suit the model you chose. Check: Is every input allowed? σ must be positive, p between 0 and 1, and sin⁻¹ or cos⁻¹ needs a number from −1 to 1. Exponential and power models need positive data. Fix: Change the value that is out of range, or choose a model that suits the data.
ERR:INVALID DIM TI's knowledge base: one or more stat plots are turned on, but the lists they use are empty. Check: A stat plot left on from a statistics question, so the error appears when you graph a function. Fix: Turn off the stat plots you are not using, or put the data back in the lists.
ERR:SYNTAX The command contains a syntax error: a misplaced function, argument, bracket or comma. Check: TI points out that subtract − and negative (−) are different keys, and using the wrong one causes this error. Then check the brackets and commas. Fix: Find the misplaced function, argument, bracket or comma and correct it.
TI-Nspire CX II: Domain error, Syntax error
Domain error An argument must be in a specified domain, and this one is not (TI's example: rand(0)). Check: Is every input allowed? σ must be positive, p between 0 and 1, and sin⁻¹ or cos⁻¹ needs a number from −1 to 1. Fix: Change the value that is out of range.
Syntax error The syntax checker found a problem. Check: A missing bracket or comma. Fix: Correct the expression and try again.
Do it in Desmos
Not in the exam. Desmos is not allowed in IGCSE exams. Use it to learn, to check an answer and to see the graph behind a question.
- Define f(x) = x^2 − 3x + 1.
- Add a table (+ → table), put x₁ values −1, −0.5, … and f(x₁) as the second column heading: Desmos fills it in.
- The points appear on the graph; the curve shows where it crosses the axis.
Open desmos.com/calculator (free, in any browser) and type:
f(x)=x^{2}-3x+1table: x_1 = -1, -0.5, 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4; y_1 = f(x_1)
Questions
Can I use a calculator for tables of values in the exam?
On Pearson Edexcel International GCSE Maths A (4MA1), yes: Paper 1H and Paper 2H both allow a calculator with no CAS. On Cambridge IGCSE 0580 (from 2025), Papers 1 and 2 are non-calculator, and the syllabus says you should have a scientific calculator for Papers 3 and 4.
What are the fx-991EX keystrokes for tables of values?
MENU 9 (Table). Then Type f(x) = X² − 3X + 1 and press =. If a g(x) line appears, press = again to leave it empty (whether g(x) is offered is a Table setting in SHIFT MENU (SETUP)). Then Start −1 =, End 4 =, Step 0.5 =. The table appears. The full steps and the other calculators are in the keystrokes section above.
Does this work on other calculators?
Yes. This page has keystrokes for the Casio fx-991EX ClassWiz, Casio fx-991CW ClassWiz, Casio fx-CG50, TI-84 Plus CE and TI-Nspire CX II. The worked example has the same answers on every model, so use it to check.
What should I write as working?
Write the maths, not the key presses: say what you are finding in normal notation (the equation, the probability statement or the integral), then the calculator's answer to the accuracy the question asks for (often 3 significant figures). Keep full accuracy in later parts.
More calculator skills
Sources
- Casio fx-991EX / fx-570EX Quick Start Guides : Casio fx-991EX ClassWiz, the fixed ROM (these models take no OS updates).
- Casio fx-991CW / fx-570CW User's Guide : Casio fx-991CW ClassWiz, the fixed ROM (these models take no OS updates).
- Casio fx-CG50 Software User's Guide, OS 3.70 (PDF) : Casio fx-CG50, OS 3.80 (menus unchanged from OS 3.60 onwards as far as we can tell).
- TI-84 Plus CE guidebook (Texas Instruments) : TI-84 Plus CE, OS 5.8.x.
- TI-Nspire CX II guidebooks (Texas Instruments) : TI-Nspire CX II, OS 6.x.
- Desmos Help Center for the Desmos functions.
Menu names are taken from each manufacturer's manual for the models shown. Menus can move slightly between OS updates: if a screen looks different on yours, the manual for your version is the reference, and please tell us so we can update this page. A calculator with no tab here has no checked steps for this skill yet. Worked-example answers were recomputed independently in Python.