adding, subtracting,multiplying, and dividing intergers

addition rules

1. If signs are the same then add and keep the sign of the numbers.

2. If the signs are different then subtract and keep the sign of the bigger number.

subtraction rules

1. Change all subtraction to addition by doing plus the opposite of the second number.

adding

If the problem is 3+-4=_ then first you subtract 3-4 which =s 1 and keep the sign of the bigger number. The bigger number is 4 and the 4 is negative so the answer is -1. Thats if the signs are different. If the signs are the same you add the 2 numbers together and keep the sign of the numbers.

examples

-5+-3=

answer

-8

-4+2=

answer

-2

subtraction

The first thing you do is always plus the opposite. To do plus the opposite you change subtraction to addition then you change the sign to the opposite of what it already is. Then you just do the rules for addition to do the rest.

examples

5--7=

answer

12

-7-9

answer

-16

multiplication rules

1. You multipy the 2 numbers then if the signs are the same the answer is positive and if the signs are different the answer is negative.

division rules

1. You divide the 2 numbers and if the signs are different the answer is negative and if the signs are the same the answer is positive.

multiplying

If the problem is 4x-2 then you first multiply the 2 numbers together. Which is 8 then since the signs are different the answer is negative so the answer is -8.

examples

-6x4=

answer

-24

-5x-2=

answer

-10

division

If the problem is -4 divided by -2 then first you divide 4 by 2 which is 2. Then since the signs are the same the answer is positive. so the answer is 2.

examples

-8/-2=

answer

4

-9/3

answer

-3

http://www.purplemath.com/modules/negative3.htm

division

equations and check

factors and greatest common factors

VOCABULARY
factors= If a number is a factor of another number it is divisible by it.


FACTORS To find out a numbers factors you need to know divisibility rules. Divisibility rules are like a short cut to finding out if a number is divisible by it or not. The number your trying to find the factors of and one are always one of the factors. To find out if a number is a factor of another number you you divide the number by the factor.
DIVISIBILITY RULES
2= if it's even 3= if the sum of the digits divisible by 3 5= if it ends in 0 or 5 6= if it is divisible by 2 and 3 9= if the sum of the digits is divisible by 9 10= if it ends in 0 11= if the 2 outside numbers add to give the middle number
EXAMPLE
multiples of 50=1,50,2,25,5,10,



GREATEST COMMON FACTOR
To find the greatest common factor (gcf) of too numbers you need to know the factors of both of the numbers (when you are first learning it then there are short cut ways). Then you find all the factors they have in common. After you know all the factors they have in common you pick the highest. Then you have the greatest common factor (gcf).
EXAMPLE
multiples of 50=1,50,2,25,5,10
multiples of 80=1,80,2,40,4,20,5,168,10


http://http://www.math.com/school/subject1/lessons/S1U3L1GL.html

exponents and scientific notation

VOCABULARY

The base is the number that is being multiplied.

The exponent is the number of times you multipy the base by.

EXPONENTS

If you are going to do exponents you need to know what the base and exponent is of the problem.Then you take the exponent and multiply the base by it's self the number of times the exponent is.Then you have your answer.

EXAMPLE: 2 to the 4th power= 16

2x2x2x2=16

SCIENTIFIC NOTATION

There is a decimal after every number so to put a number in scientific notation you move the decimal over as many times as you need to get the decimal right after the first number.Then you take off all the zeros.Then add the exponent always remember that the base is ALWAYS ten and the exponent is how many times you had to move the decimal over to get it after the first number.

REAL LIFE EXAMPLE:

The distance from the earth to the sun it 10 to the power of 6