3 Getting to know your calculator
In the following activities, you’ll learn how to use your calculator. You have plenty of options when it comes to what calculator to use and you may find it easier to use the one that you are most familiar with. This maybe a calculator on your mobile phone, on your computer or tablet, an online calculator, or a handheld calculator.
Let’s start with an easy calculation that you can check in your head to make sure your calculator is working properly. If you are using an online or computer-based calculator, you will be able to make entries using your keyboard or by clicking on the screen buttons. Just make sure that your cursor is positioned correctly before you start. Now click on or press the following keys: 
.
Depending upon what calculator you are using, the sum that you have input may remain on the display after you have pressed the equals signs or only the answer may appear.
You should get the answer 7!
Once the calculation is complete, it needs to be cleared before the
next calculation can be performed. You clear a calculation by clicking on
the 
button. Do this now; your last calculation should
disappear.
Correcting mistakes
Suppose you want to calculate 37 − 19, but you mistype and enter 37 − 29 by mistake. You may be able to correct this mistake rather than starting from scratch and re-entering the whole calculation. Look now to see if you have a backwards-facing arrow or a delete button (del) on your calculator. If you don’t, it just means that you need to start again, so it is not a problem.
Arithmetic on your calculator
Now you’re ready to do arithmetic on your calculator. You may find Table 1 helpful in finding the correct button or key if you are using the keyboard.
| Mathematical operation | Calculator button | Keyboard key |
|---|---|---|
| + |  | Shift and ‘=’ on the main keyboard or ‘+’ on the number pad |
| – |  | ‘-’ (the key to the left of ‘=’) on the main keyboard or on the number pad |
| × |  | Shift and ‘8’ on the main keyboard or ‘*’ on the number pad |
 |  | ‘/’ on the main keyboard or on the number pad |
| = |  | Enter |
| Clear | | Backspace (as often as needed to clear all entries) |
Note that if you are using a computer-based calculator, the multiplication symbol may be shown as a * rather than ×.
In this activity, you are going to do several straightforward calculations to make sure that you can get your calculator to work properly. Check the answer in your head so that you know what your calculator should show. Remember to clear the calculation before you enter each new calculation.
Activity 5 A few arithmetic problems
Badge activity
This is the second of four badge activities.
In this activity you are going to do several straightforward calculations to make sure that you can get your calculator to work properly. Check the answer in your head so that you know what your calculator should show. Remember to clear the calculation before you enter each new calculation.
Comment
How did that go? Hopefully you found it fairly straightforward – but it you didn’t, don’t worry. The next section of the course will give you a chance to become more confident using a calculator.