Calculators do a lot of the hard work for you, so why would you need to use a calculator more efficiently? Using a calculator efficiently is a good habit to get into, as soon as you can. Efficient use of your calculator can save you time in exams, save you time when you’re doing homework, and give you more accurate answers.
Take some time to get to know your calculator and what it can do for you. Let’s look at an example. Suppose you want to calculate correct to 2 d.p:
3.16 + 5.14 divided by 1.87 + 0.33
You could either do:
3.16 + 5.14 = 8.3
1.87 + 0.33 = 2.2
8.3/2.2 = 3.77 (correct to 2 d.p.)
Or:
(3.16 + 5.14)/(1.87 + 0.33) = 3.77 (correct to 2 d.p.)
In this case you can either do 3 sums, or just one. With these simple numbers it doesn’t matter too much. Let’s look at another example, calculated correct to 3 d.p:
11.2/1.7 divided by 2π
You could do:
11.2/1.7 = 6.588235294 (full display on calculator)
2 x π = 6.283185307 (full display on calculator)
6.588235294/6.283185307 = 1.048550213 (full display on calculator)
Answer: 1.049 (to 3 d.p.)
But it is much easier to do the calculation in one go:
(11.2/1.7)/ 2π = 1.048550213
Answer: 1.049 (to 3 d.p.)
Notes
1. The / means divided by
2. The brackets tell your calculator which part of the calculation to do first
3. Check how your calculator treats 2π. You may be able to enter 2 and then π, with no operator in between, and your calculator will automatically multiply them before dividing the result from the brackets by 2π. If not, then you need to enter the sum as: (11.2/1.7)/ (2 x π) = 1.048550213
4. Doing the sum in one calculation is much quicker
5. There’s no risk of getting a wrong answer from writing down intermediate results incorrectly
6. You don’t lose any accuracy when you do the sum in one calculation
If you’re not sure what all the buttons are for on your calculator, have a look in the instruction book. If you can’t find it, don’t worry; you’ll almost certainly be able to find one on the internet. Check on the manufacturer’s website.
The main thing is, get to know your calculator and what it can do for you. Using your calculator efficiently can save you time in exams. Knowing how to use your calculator effectively can reduce the risk of making or introducing errors into calculations in exams.
Efficient use of calculators can save you time and help you maximise your marks.