1.10.1 Using a Calculator
Calculator
All the buttons and features on a calculator might be a little scary if you’ve never used one before.
However, the fundamentals are essentially the same whether you’re using a regular calculator or a scientific calculator. When you are familiar with the functions of the buttons and how to use them for various calculations, you will feel completely at ease using your calculator anytime you require it.
The following notes apply to most, if not all, scientific calculators, however the pictures are based on the Casio fx-570VN plus.
Casio fx-570VN plus
Mode/Setup
Make sure you understand how to switch your calculator’s mode.
Most calculators are set to “Math” mode by default, which is indicated by the word Math across the top of the display. You can see in the above picture.
In Math mode you can switch the answer between exact and decimal by pressing the (SD) button
The “Angle Unit” must be degrees, as shown in the preceding image by the “D” sign at the top of the display.
Check that you can choose between “exact” and “approximate” responses (fractions, surds, in terms of, etc.)
Templates
The fraction button, square root, square and power are mostly shortcut buttons.
SHIFT and these buttons can also be used to access functions like mixed numbers, cube roots, cube and nth roots.
To enter time in hours, minutes and seconds use (°”’) button
Trigonometry (Sin/cos/tan)
Use SHIFT along with the keys to find angles
To enter an angle, always use a closed bracket.
Brackets are essential if there is something more to type after sin/cos/tan.
Standard form and \( \pi \)
To put number in standard form, use \( \times 10^x \) button.
To enter \( \pi \) use along with the SHIFT button.
Brackets and negative numbers
Always use brackets for negative numbers
Use (-) button for negative numbers
Check the difference between \( -3^2 \) and \( (-3)^2 \) by calculator
Memory
The Ans (answer) button is quite beneficial, particularly when working with decimals in the middle of solutions, which you should avoid rounding until you have your final result.
Ans remembers the last solution the calculator generated.
Table
To solve “Complete the table and draw the graph type questions,” use the table mode.
Judgment and special features
Use your calculator to perform one calculation at a time as a general guideline.
However, you can make a decision based on how many marks are available in the question and if a question requires you to “write down all the figures on your calculator display.”
It is better to write too much than not enough!
Practice
Get a calculator early and learn how to use it by practicing the variety of questions you are likely to come across
Worked example:
Use your calculator to work out \( \sqrt[]{1-(sin(33))^2} \), and give your answer correct to 3 decimal places.
Type in your calculator \( \sqrt[]{1-(sin(33))^2} \)
Press (=) button
Round to \( 3 \) decimal places by using an appropriate rule
\( 0.839 \)
\( \sqrt[]{1-(sin(33))^2}=0.839 \)
Test yourself
Question 1:
Use your calculator to work out
\( \frac{ \sqrt{4.69} }{0.43^3+sin (45)} \)
Give your answer as a decimal.
Write down all the figures on your calculator display.
[2]
Question 2:
Calculate
\( \sqrt[3]{8.1^2-1.3^{0.8}} \)
[1]
Question 3:
Use your calculator to work out
\( \frac{16.379-0.879}{4.2} \times 1.241 \)
Give your answer correct to \( 2 \) significant figures.
[2]
Question 4:
Use a calculator to find the decimal value of
\( \frac{\sqrt[]{29-3 \times 32^{0.4} } }{3} \)
[1]
Question 5:
Complete the table of values for \( y=x^3-6x+1 \)
[3]