Skills · GDC Walkthroughs

IB Maths GDC guide: TI-Nspire and fx-CG50 keystrokes

Quick answer: you can use a GDC in every IB Maths AI paper and in AA Paper 2 (and HL Paper 3); AA Paper 1 is calculator-free. Pick a skill below, then your calculator, and follow the numbered keys.

Six flagship GDC skills, each shown as numbered keystroke pills on the TI-Nspire CX and the Casio fx-CG50. Tap a tab to switch calculators. For every other skill (and the TI-84 Plus CE), see Calculator skills. To learn a calculator from scratch, work through the free calculator lessons: twelve each for the fx-CG50 and the TI-84 Plus CE. To check a graph or a regression on a computer, use our free graphing calculator. Video walkthroughs land per topic — leave a note if there's one you want next. New to the GDC? Start with the core toolkits: GDC basics, LaTeX and command terms.

1. Normal distribution — PDF and CDF

SL AI · SL AA · HL AI · HL AA
Goal: Given $X \sim N(\mu, \sigma^2)$, compute $P(X < a)$, $P(a < X < b)$, or the inverse $x$ such that $P(X < x) = p$.
1
HOME14
Open a new Calculator page from the home screen.
2
MENU65
Menu → 6 Statistics → 5 Distributions.
3
2forNormal Cdf
Pick Normal Cdf for a probability interval, or Normal PDF (1) for the density value.
4
LowerUpperμσ
Enter Lower = $a$, Upper = $b$ (or -inf/inf via πcatalog), then $\mu$ and $\sigma$.
5
enter
The probability appears. For inverse (find $x$ from $p$), use Inverse Normal — menu item 3.
1
MENU2
Open the Statistics menu icon (2).
2
F5DIST
Press DIST (F5). If not visible press F6 to page across.
3
F1NORMF2Ncd
Pick NORM (F1) → Ncd (F2) for CDF. For inverse: InvN (F3).
4
LowerUpperσμ
Note Casio's order — Lower, Upper, $\sigma$, $\mu$ (not $\mu, \sigma$).
5
EXE
Reads $p$. Save it to a variable with → A if you need it later.
▶ YouTubeVideo demo coming soon — request this one.

2. Linear regression — $y = ax + b$ and correlation $r$

SL AI · HL AI · SL AA · HL AA
Goal: Given paired data $(x_i, y_i)$, find the least-squares line and Pearson's $r$.
1
HOME13
Open Lists & Spreadsheet.
2
Type x-values in Ay-values in B
Name columns xlist / ylist in the header row so future menus find them.
3
MENU413
Menu → 4 Statistics → 1 Stat Calculations → 3 Linear Regression (mx+b).
4
X List: xlistY List: ylistOK
The equation, $r$, and $r^2$ appear in columns C-D. Read $a$, $b$ from the output.
1
MENU2
Enter Statistics.
2
x-values in List 1y-values in List 2
Type the two paired lists.
3
F2CALCF3REG
CALC (F2) → REG (F3).
4
F1XF1ax+b
Pick X then the a·x + b model. Casio shows $a$, $b$, $r$, $r^2$ instantly.
▶ YouTubeVideo demo coming soon — request this one.

3. Solve equation numerically

All courses · fastest path to $x$ when algebra won't cooperate
Goal: Given $f(x) = g(x)$, find every real root — even where algebra is messy.
1
HOME14
Open a Calculator page.
2
MENU31
Menu → 3 Algebra → 1 Solve.
3
solve( expr = 0, x )
Type e.g. solve(x^3 - 4x + 1 = 0, x). For a range: solve(..., x) | -3 < x < 3.
4
enter
All roots in the range are returned. For a graph-based check, use Graphs app → Analyze → Zero.
1
MENUA
Open Equation (icon A).
2
F3SOLVER
SOLVER (F3) for a general expression.
3
Expression = 0
Rewrite the equation so RHS is 0, type it in, set an initial guess in X.
4
F6SOLVE
Press F6. For all roots repeat with different starting guesses (or use Graph → G-Solv → Root).
▶ YouTubeVideo demo coming soon.

4. Two-sample t-test — compare means

HL AI · SL AI
Goal: Given two samples, test $H_0: \mu_1 = \mu_2$ against $H_1: \mu_1 > \mu_2$ (or ≠). Output the p-value.
1
Enter data in xlist1, xlist2
Open Lists & Spreadsheet, name your two lists.
2
MENU444
Menu → 4 Statistics → 4 Stat Tests → 4 2-Sample t-Test.
3
Data / StatsList1, List2Alt: μ1 > μ2Pooled: Yes
Choose Data, pick lists, set the alternative hypothesis, set Pooled = Yes: in IB exams the two population variances are assumed equal.
4
OK
Read the PVal from the results table.
1
MENU2
Open Statistics. Populate List 1 and List 2.
2
F3TESTF2t
TEST (F3) → t (F2).
3
F22-SAMPLE
Choose 2-SAMPLE (F2). Full path: F3 (TEST) → F2 (t) → F2 (2-SAMPLE).
4
μ1 > μ2Pooled: OnEXE
Set the alternative, turn pooling on (the IB test is pooled), press EXE. Read p.
▶ YouTubeVideo demo coming soon.

5. Numerical integration — $\displaystyle\int_a^b f(x)\,dx$

All courses · area / volume / work
Goal: Evaluate a definite integral to 3 s.f. when antiderivatives are tricky.
1
HOME14
Calculator page.
2
MENU43
Menu → 4 Calculus → 3 Numerical Integral. (Or type the integral template directly.)
3
abf(x)x
Fill in the limits, expression and variable.
4
enter
Answer appears as a decimal. Convert with ctrl-enter or ▸approx.
1
MENU1
Open Run-Matrix.
2
OPTNF4CALCF4∫dx
OPTN → CALC (F4) → ∫dx (F4).
3
∫(f(x), a, b)
Fill the template. On CG50 the syntax is ∫(f, a, b) — no explicit variable needed.
4
EXE
Definite value returned.
▶ YouTubeVideo demo coming soon.

6. Matrix inverse — $A^{-1}$ and solving $A\mathbf{x} = \mathbf{b}$

HL AI · HL AA
Goal: Find $A^{-1}$ for an $n \times n$ matrix; solve $A\mathbf{x} = \mathbf{b}$ as $\mathbf{x} = A^{-1}\mathbf{b}$.
1
HOME14
Calculator page.
2
templatesmatrix
Press templates (the button just below ctrl), pick the matrix icon, set the size.
3
a11 … ann→A
Enter the entries, then store with ctrl-var as A.
4
A^-1enter
Just type A^-1 (caret + minus + one). For the system, type A^-1 · b.
1
MENU1
Run-Matrix mode.
2
F1MAT
Press MAT (F1) to open the matrix editor.
3
Set Mat A dimensionsEnter entries
Choose Mat A, set rows/cols, type entries. EXE to save.
4
EXITMat ASHIFTx⁻¹EXE
Back on the run screen: Mat A → SHIFT + x⁻¹. The inverse prints as a fresh matrix.
▶ YouTubeVideo demo coming soon.
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