Use a calculator correctly and efficiently
So the good news is in certain exams you are able to use a calculator, however its only useful if you know how to use it. Calculators vary with regards to button positioning and the symbols used in certain cases but fundamentally they all have the same key buttons. The following should be of use to prevent any calculator errors.
BODMAS and the BRACKET BUTTONS
- This is really important even when you want to work out something simple like:
- You can't just press: - it will be completely wrong!
- The calculator follows BODMAS, so it'll think that you mean
- Th secret is to OVERRIDE the automatic BODMAS order of operations using the BRACKETS BUTTONS.
- So all you have to do is write in a couple of pairs of brackets into the expression:
- Just type:
Its OK to have brackets within other brackets too. As a rule you can't cause trouble by putting too many brackets in, so long as they always go in pairs.
The FRACTION BUTTON
Use this button as much as possible in the calculator papers, it's very easy and extremely useful.
- To enter press
- To enter 1 press
- To work out x press
- To reduce a fraction to its lowest terms enter it as as in step 1 and then press
- To convert between mixed and top-heavy fractions press
The MEMORY BUTTONS
These are really useful for keeping a number you've just calculated, so you can use it again shortly afterwards. Different calculators have different buttons but generally you will either have the , and buttons or alternatively an button.
The difference being that the first requires you to specifically ask the calculator to store the number by pressing and then recalling it at a later date using . Where as the other automatically stores the answer to the previous calculation and can be called up by pressing (limitations as only calls up the last calculation, the last time you pressed =).
What Does The Answer Mean?
This sounds silly but after all your efforts on the calculator it would be annoying to then loose marks by not thinking through what the answer actually means and the units it should be in.
For instance if your calculator shows an answer of say and you are answering a money question then an answer of $3.2 would loose you marks, you should of course write $3.20. Alternatively if you are talking about the number of people then the correct answer is likely to be 3 people, an examiner might get concerned about how you are going to create 0.2 of a person for such a task!
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