1.11 Electronic calculators
- Syllabus
- 2017
- Topic
- 1.11
- Level
- Higher
Learning objectives
Use a scientific calculator accurately
A scientific calculator evaluates a mathematical expression according to operation hierarchy. Accurate use begins by translating the printed expression into an unambiguous key sequence.
| Stage | Reliable action |
|---|---|
| plan | identify numerator, denominator, powers, roots and brackets |
| enter | use bracket keys to preserve the printed structure |
| inspect | check the display before pressing equals |
| record | copy all requested display figures before rounding |
| verify | estimate the size and sign of the result |
For ((125.6)/(4.7))2, enter the division in brackets before squaring. For a fraction containing several terms, bracket the entire numerator and denominator.
Store or retain unrounded intermediate values. If the question says ‘write down all the figures on your calculator display’, do not shorten the decimal or give a rounded form.
Check angle mode before trigonometry and use the calculator's scientific-notation, fraction/decimal and previous-answer functions deliberately rather than assuming their state.
A calculator follows the entered syntax, not the intended expression. A plausible-looking display is not proof of correct entry; brackets and an independent estimate are essential.