1 Doing calculations, with or without a calculator
Most science modules assume that you can add, subtract, multiply and divide whole numbers.
Check that you can do this by carrying out the following four calculations without using a calculator:
You should have obtained the following answers:
Now check that you can use your calculator to obtain the same answers as before. You are likely to need to enter the numbers and symbols in a simple sequence from left to right (for example, ‘9’ then ‘+’ then ‘3’) and then to press the ‘=’ key. However, some calculators use the symbol ‘*’ instead of ‘’ for multiplication and ‘/’ instead of ‘’ for division, and at least one model requires users to press ‘Enter’ instead of ‘=’ in order to obtain the answer. Check your calculator now!
Most scientific calculations are rather more complicated than those discussed above, in that they involve several steps. In some of these calculations, for example:
you simply need to start at the left and work through to the right. So in the first example, adding 9 and 3 gives 12, adding another 5 gives 17 and adding another 2 gives the final answer of 19.
Check that you can do the following three calculations both without and with a calculator:
You should have obtained the following answers:
Question 1.1
Use your calculator to find the following:
- a.
- b.
(Note that you do not have to press ‘=’ after the first addition (38 + 92), though if you do the final answer should be the same; check this for yourself.)
- b.
- c.
- d.
- e.
- f.