Is a Graphing Calculator Worth It?

A graphing calculator costs roughly five to ten times what a good scientific calculator does. Sometimes that is unavoidable and sometimes it is money spent on a machine that will be used as an expensive scientific calculator. It is worth being clear which situation you are in.

What a graphing calculator adds

Function plotting

The obvious one: enter an equation, see its shape, trace along it, find intercepts and turning points. For anyone studying functions this is not a convenience, it is the subject made visible.

Multiple representations at once

The more significant capability. A graphing calculator can show a function as an equation, a table of values and a curve simultaneously, and change all three when you change one. That connection is the thing students most often miss when working on paper.

Statistics with real data sets

Entering forty data points into a scientific calculator is painful and error-prone. On a graphing calculator they go into a list you can see, edit and re-use, with regression and plots available from that list.

Matrices and systems

Solving a three-by-three system, inverting a matrix, or working with transformations is practical on a graphing machine and tedious on a scientific one.

When it is the right purchase

• The course explicitly requires one, or the teacher demonstrates on one.
• The syllabus covers calculus, statistics with data sets, or matrices.
• The exam permits it — and permits the specific model.
• The student will use it for more than one year. The cost is easier to justify across three years than one term.

When it is not

• The exam prohibits graphing calculators. This is common and it makes the purchase actively counterproductive, because familiarity with the wrong machine is worse than no machine.
• The course is arithmetic, general science, or business maths. A 12-digit desktop or a two-line scientific model does that work better and faster.
• It is being bought “to be ready” for a course two years away. Approved model lists change and the machine will be older when it is needed.

CAS or non-CAS

This is the decision people get wrong. A CAS (computer algebra system) model manipulates algebra symbolically: it will factorise, expand and solve exactly rather than numerically.

It is a genuinely more capable machine. It is also excluded from some exams that permit non-CAS graphing calculators, and the two versions of the same model look nearly identical. If there is any chance of an exam restriction, check before buying, because this is not a setting you can turn off.

The learning curve is real

A graphing calculator has menus. A student handed one the week before an exam will not use it well. If you are buying one, buy it at the start of the course so the machine is familiar before it matters.

Practical points

• Rechargeable versus AAA. Rechargeable models are convenient and need charging before exam day. Battery models need spares.
• Screen. Colour screens are easier to read for multiple plotted functions. Monochrome models are cheaper and have longer battery life.
• Case. These are expensive machines carried in school bags. A hard case is not optional.
• Reset before an exam where required, and know the key sequence.

The honest summary

If a course requires it, buy it early and learn it. If a course does not require it, a good two-line or four-line scientific calculator will serve better, cost less, and be permitted everywhere.

See our Graphing Calculators, or compare against the Scientific Calculators range. If you have a syllabus in front of you, send us the wording.