Skills · GDC Walkthroughs
Every keystroke, in order — for both calculators.
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. Video walkthroughs land per topic — leave a note if there's one you want next.
Normal PDF/CDF
Linear regression
Solve equation
2-sample t-test
Numerical integration
Matrix inverse
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 $P(X < x) = p$.
📱 TI-Nspire CX
🧮 Casio fx-CG50
1
HOME 1 4
Open a new Calculator page from the home screen.
2
MENU 6 5
Menu → 6 Statistics → 5 Distributions .
3
2 for Normal Cdf
Pick Normal Cdf for a probability interval, or Normal PDF (1) for the density value.
4
Lower Upper μ σ
Enter Lower = $a$, Upper = $b$ (or -inf/inf via π catalog ), then $\mu$ and $\sigma$.
5
enter
The probability appears. For inverse (find $x$ from $p$), use Inverse Normal — menu item 3.
1
MENU 2
Open the Statistics menu icon (2).
2
F5 DIST
Press DIST (F5). If not visible press F6 to page across.
3
F1 NORM F2 Ncd
Pick NORM (F1) → Ncd (F2) for CDF. For inverse: InvN (F3).
4
Lower Upper σ μ
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.
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 $r$.
📱 TI-Nspire CX
🧮 Casio fx-CG50
1
HOME 1 3
Open Lists & Spreadsheet .
2
Type x-values in A y-values in B
Name columns xlist / ylist in the header row so future menus find them.
3
MENU 4 1 3
Menu → 4 Statistics → 1 Stat Calculations → 3 Linear Regression (mx+b) .
4
X List: xlist Y List: ylist OK
The equation, $r$, and $r^2$ appear in columns C-D. Read $a$, $b$ from the output.
2
x-values in List 1 y-values in List 2
Type the two paired lists.
3
F2 CALC F3 REG
CALC (F2) → REG (F3).
4
F1 X F1 ax+b
Pick X then the a·x + b model. Casio shows $a$, $b$, $r$, $r^2$ instantly.
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.
📱 TI-Nspire CX
🧮 Casio fx-CG50
1
HOME 1 4
Open a Calculator page.
2
MENU 3 1
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
MENU A
Open Equation (icon A).
2
F3 SOLVER
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
F6 SOLVE
Press F6. For all roots repeat with different starting guesses (or use Graph → G-Solv → Root ).
▶ YouTube Video 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.
📱 TI-Nspire CX
🧮 Casio fx-CG50
1
Enter data in xlist1, xlist2
Open Lists & Spreadsheet , name your two lists.
2
MENU 4 4 4
Menu → 4 Statistics → 4 Stat Tests → 4 2-Sample t-Test .
3
Data / Stats List1, List2 Alt: μ1 > μ2 Pooled: No
Choose Data , pick lists, set the alternative hypothesis, leave Pooled = No unless variances are known equal.
4
OK
Read the PVal from the results table.
1
MENU 2
Open Statistics . Populate List 1 and List 2.
2
F3 TEST F2 t
TEST (F3) → t (F2).
3
F2 2-S
Choose 2-S (2-Sample) → F2.
4
μ1 > μ2 Pooled: Off EXE
Set the alternative, keep pooling off, press EXE . Read p .
▶ YouTube Video 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.
📱 TI-Nspire CX
🧮 Casio fx-CG50
2
MENU 4 3
Menu → 4 Calculus → 3 Numerical Integral . (Or type the integral template directly.)
3
a b f(x) x
Fill in the limits, expression and variable.
4
enter
Answer appears as a decimal. Convert with ctrl-enter or ▸approx .
2
OPTN F4 CALC F4 ∫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.
▶ YouTube Video 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 $\mathbf{x} = A^{-1}\mathbf{b}$.
📱 TI-Nspire CX
🧮 Casio fx-CG50
2
templates matrix
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^-1 enter
Just type A^-1 (caret + minus + one). For the system, type A^-1 · b.
2
F1 MAT
Press MAT (F1) to open the matrix editor.
3
Set Mat A dimensions Enter entries
Choose Mat A , set rows/cols, type entries. EXE to save.
4
EXIT Mat A SHIFT x⁻¹ EXE
Back on the run screen: Mat A → SHIFT + x⁻¹ . The inverse prints as a fresh matrix.
▶ YouTube Video demo coming soon.