Using a Calculator Flashcards

All 5 cards in this deck

What are the steps to work out a calculation with a fraction bar on your calculator?

e.g. $\dfrac{9.8+6.8}{4.2\times 2.1}$ as a decimal

1. Key the top inside brackets: $(9.8+6.8)=16.6$
2. Key the bottom inside brackets: $(4.2\times 2.1)=8.82$
3. Divide, pressing S⇔D for a decimal: $1.8820861\ldots$

A question says "write down all the figures on your calculator display". What must you write?

Every digit exactly as it appears on the display, with no rounding.
If the display shows a fraction, press S⇔D first to get the decimal.

True or false? Typing $595 \div 4.08 \times 5.32$ into a calculator gives the value of $\dfrac{595}{4.08 \times 5.32}$.

False. The calculator divides and then multiplies, so you must key $595 \div (4.08 \times 5.32)$.

On a calculator, how much of a calculation does the square root sign cover?

e.g. $\sqrt{\dfrac{13.82}{4.06}}$

Everything keyed inside the root's brackets, so the whole fraction goes under the root: $\sqrt{(13.82 \div 4.06)} = 1.844977205\ldots$

What are the steps to find the value of a formula on your calculator and give the answer to the accuracy asked for?

e.g. $A = \pi r^2$ when $r = 3.2$, to 1 decimal place

1. Substitute the values: $A = \pi \times 3.2^2$
2. Key it in using the $\pi$ and $x^2$ keys: $32.16990877\ldots$
3. Round to the accuracy asked: $A = 32.2$