Scientific or graphing?
A scientific calculator handles expressions such as fractions, powers and trigonometric functions. A graphing calculator adds graphing workflows and may be required by some courses. The Casio and TI models in this collection are scientific calculators; do not choose one as a substitute if your teacher requires graphing.
Choose a display you can check
A textbook-style display can make fractions and mathematical expressions easier to recognise. A two-line display separates your input from the result. Compare the fx-300ES PLUS and TI-30X IIS layouts, and choose the workflow that helps you catch entry mistakes.
Match the advanced tools to the course
For routine scientific calculations, a simpler model may be sufficient. For equations, matrices and more advanced statistics, consider a model such as the fx-991CW. Confirm the exact operations in the manual rather than choosing by a large advertised function count.
Check power and exam rules
The three models listed here use solar power with battery backup. Keep the battery in good condition and follow the manual. Exam permission is a separate question: check the exact model against the current exam-provider rules and your school requirements.
Try a small set of typical problems
Before making a final decision, check how the model enters a fraction, a negative number, a power and a trigonometric expression. Learn the difference between degrees and radians. Keep the manual available; familiar controls are often more valuable than an unused extra feature.
Editorial guide, not a sponsored review. Check the exact model manual and current course requirements before choosing. The store remains a demo; prices and checkout are for testing.