TI-Nspire CX II field manual for IB Math
Common mistakes to avoid
The wrong minus key, the wrong angle mode, the wrong standard deviation, and each device's own classic traps, and what each wrong answer looks like.
Entry templates hold the cursor. The key opens an exponent box, and fraction templates do the same: each box holds the cursor. Type 2^5 then +3 straight away, and the +3 lands inside the exponent: 25+3=256, not 25+3=35. Press to step out before continuing the line.
Type every operator. The Nspire never assumes one. Multiplication is never implied: xy is a single variable named xy, so press yourself: x·(x+1). And an unbracketed denominator follows the order of operations, not your reading order: 20/4·6 divides only by the 4 and gives 30. Dividing by the whole product needs brackets: 20/(4·6) is 65.
The wrong angle mode. The Nspire ships in Radian mode, so sin(30) means 30 radians: a degrees problem comes back as −0.988: impossible for an acute angle, and the badge at the top said RAD all along. Switch it in Document Settings (AI SL: Degree, once) and the same line gives sin(30∘)=0.5.
A fraction when you wanted a decimal. In Auto mode exact results stay exact: 32+61 comes back as 65. When the question wants 3 significant figures, evaluate with (≈) instead of .
The wrong standard deviation. One-Variable Statistics prints two: σx (divide by n) and sx (divide by n−1). Which one an IB question wants depends on whether the data is the whole population (σx) or only a sample of it (sx). And the variance is never printed: square the standard deviation yourself.