Adding
(-10) + 17 =
7
387-258 =
129
(-7) x 4 =
-28
(-24) ÷ 8 =
-3
adding positive and negative number rules
- + - = - Combine the addends - sum has the same sign as both addends
+ + + = + Combine the addends - sum has the same sign as both addends
- + + = find the difference - whichever addend has the greater absolute value determines the sign of the sum
+ + - + find the difference - whichever addend has the greater absolute value determines the sign of the sum
(-32.5) + (-25.37) =
-57.87
25 - (-15) =
40
(-6) x (-9) =
54
(-42) ÷ (-6) =
7
Subtracting positive and negative number rules
Steps to follow
1. Turn the subtraction problem into an addition problem using the additive inverse.
2. Follow the rules of adding positive and negative numbers.
(-102)+ 53.9 =
-48.1
1.2
(-3.5) x (-0.7) =
2.45
(-25.5) ÷ (-5) =
5.1
Multiplying positive and negative numbers
- x + = -
- x - = +
(-3/5) + (-2/15) =
-11/15
(-42.87) - 13.19 =
-56.06
25.4 x (-18) =
-457.2
(-3/4) ÷ (-8/9) =
27/32
Dividing positive and negative numbers
- ÷ - = +
- ÷ + = -
+ ÷ - =-
+ ÷ + = +
(-17/20) + 1/4 =
(-1/4) - 7/8 =
-9/8 or -1 1/8
(-3/9) x (-5/6) =
15/54 or 5/18
2/7 ÷ 3 1/4 =
8/91
decimals and fractions
adding:
When adding fractions convert fractions so, both terms have the same denominator
When adding decimals align you terms place values
Subtracting:
When subtracting fractions convert fractions so, both terms have the same denominator
When subtracting decimals align you terms place values
Multiplying:
When multiplying fractions multiply straight across the numerators and straight across the denominators
When multiplying decimals your product will have as many decimal places as the total decimal places in both of your factors
Dividing:
When dividng fractions multiply by the reciprocal of the divisor