Idiot\'s Guides Basic Math and Pre-Algebra

34 Part 1: The World of Numbers

Ready for a more complicated problem? Try this example.

Example 2: 7 v 20 – 2 v 4 + 3^2 + 12 z 4

There are no parentheses, so take care of the exponent first. 3^2 = 9, so the problem

becomes 7 v 20 – 2 v 4 + 9 + 12 z 4. Next, do multiplication and division as you

come to them, starting on the left and moving across the line: first 7 v 20, then

2 v 4, and then 12 z 4.

7 v 20 – 2 v 4 + 9 + 12 z 4

= 140 – 2 v 4 + 9 + 12 z 4

= 140 – 8 + 9 + 12 z 4

= 140 – 8 + 9 + 3

When all the multiplying and dividing are taken care of, return to the beginning of

the line, and do addition and subtraction as you come to them.

140 – 8 + 9 + 3

= 132 + 9 + 3

= 141 + 3

= 144

Sometimes you’ll see more than one set of grouping symbols in the same problem, and sometimes

you may see one set inside another. Different types of grouping symbols are often used to help you

tell which is which.

Example 3: 7[120 – 2(4 + 3)^2 + 12] z 2

This problem uses parentheses inside of brackets. Brackets have the same meaning

as parentheses. They’re just a different shape so you don’t get confused. Work from

the inside out. Notice that there are numbers in front of the parentheses and brackets

with no operation sign in between. This is another way of writing multiplication.

Do what’s in the parentheses first.

7[120 – 2(4 + 3)^2 + 12] z 2

= 7[120 – 2(7)^2 + 12] z 2