A calculator evaluates the expression entered, so match every numerator, denominator and exponent with the intended brackets. Keep full intermediate precision by using the answer or memory function, then round once at the end. Example For (7.82-1.6)/(2.4+0.7), enter (7.82-1.6) (2.4+0.7). This gives 19.109677, or 19.1 to 3 significant figures. An estimate of 60/3=20 checks the scale. In trigonometry, set degree mode when the angle is in degrees. A displayed decimal is an approximation, so retain an exact fraction, surd or multiple of pi when the question asks for an exact value. Interpret the display in context: 4.8 dollars is written as $4.80, and 3.25 hours is 3 hours 15 minutes. Enter 2 hours 30 minutes as 2.5 hours, not 2.30.

A calculator evaluates the expression entered, so match every numerator, denominator and exponent with the intended brackets. Keep full intermediate precision by using the answer or memory function, then round once at the end.

For $\frac{7.8^2-1.6}{2.4+0.7}$, enter $(7.8^2-1.6)\div(2.4+0.7)$. This gives $19.109677\ldots$, or $19.1$ to 3 significant figures. An estimate of $60/3=20$ checks the scale.

In trigonometry, set degree mode when the angle is in degrees. A displayed decimal is an approximation, so retain an exact fraction, surd or multiple of pi when the question asks for an exact value.

Interpret the display in context: $4.8$ dollars is written as $4.80, and $3.25$ hours is 3 hours 15 minutes. Enter 2 hours 30 minutes as $2.5$ hours, not $2.30$.

Real Numbers

Cambridge IGCSE Mathematics 0580. Initial catalogue covers the assessed demands of February/March 2026 Paper 22; further Core and Extended mappings require paper-level scope review.

Brackets, memory and sensible accuracy

Brackets, memory and sensible accuracy