To crunch the numbers means to perform calculations before making a decision or estimate.
Accountants, financial managers or financial analysts have to crunch the numbers (robić obliczenia) as their job requires to arrive at some financial decisions which are essential for the company’s success.
This post is aiming at reminding you of basic maths if you feel a little rusty in this area.
INTEGERS
An integer (liczba całkowita) is a whole number, positive or negative, e.g.:
-3, -2, -1, 0, 1, 2, 3, 4, 5
FRACTIONS & DECIMALS
Fractions (ułamki) (1/2, 1/4, 7/9, 15/29) and decimals (ułamki dziesiętne) (0.2, 1.7, 7.89) show parts of a whole. Fractions are turned into decimals by dividing the numerator (licznik) by the dominator (mianownik) (the top line by the bottom line).
If you want to turn decimals into fractions, you need to remember that places after decimal point stand for tenths, hundredths, thousandths and so on.
SIGNIFICANT DIGITS
If a decimal number has too many digits, you can round it to a specific number of significant digits (znaczące cyfry) by discarding digits using this rule:
If the first digit to be discarded is greater or equal to five, then add one to the previous digit. Otherwise the previous digit is unchanged. For example:
187.392 rounded to 187.39
187.392 rounded to 187.4
187.392 rounded to 187
BRACKETS
A. Do things in brackets before doing things outside them.
Use the rule A, do things in this order.
- powers (potęgi) and roots (pierwiastki)
- multiplications (mnożenia) and divisions (dzielenia), working from left to right
- additions (dodawania) and substractions (odejmowania), working from left to right
Examples:
a. 3+6 x 8 =51 –> 3+ (6 x 8) = 51
b. (3+6) x 8 = 72
c. 12-4 : 2 =10 –> 12 – (4 : 2) = 10
d. (12-4) : 2 = 4
RECIPROCALS
The reciprocal (odwrotność liczby) of a number is 1 divided by that number, e.g.: the reciprocal of 2 is 1/2.
PERCENTAGES & RATIOS
Percentages indicate the relative size or proportion of items rather than their absolute size.
Workers Supervisors Directors Total
Absolute numbers 10 6 4 20
Percentages 50% 30% 20% 100%
A Proportion means writing a percentage as a proportion of 1 – as a decimal.
e.g. 0.2 is the proportion of the directors
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