Addition: from 2.1 and 2.3:
Pos + pos = pos (add as usual)
Neg + neg = neg (add the absolute values)
1. Signs the same, add absolute values and keep the sign
2. Signs different, subtract absolute values and take the sign of the
number with a greater absolute value.
Subtraction: from 2.2 and 2.3
Neg – pos = neg (add the absolute values)
Pos – neg = pos (add the absolute values)
1. In general, add the opposite: change the operation to addition
and the sign of the subtrahend (second number)
Fact Families: from 2.4
All fact families follow the same format. For addition and
subtraction:
Addition
Subtraction
a+b=c
c-a=b
b+a=c
c-b=a
Notice that the ‘c’ is always the sum and always the minuend (first
number in subtraction.)
To find an unknown in an equation, find the fact family member that
gets the ‘n’ at the end.
Graphing: from 2.5
Rene DesCartes invented the Cartesian Coordinate System
The origin is where the 2 axes intersect (0,0)
The x-axis is horizontal. It is always the first coordinate graphed.
The y-axis is vertical
Ordered pair tells the address of a point on the graph. It is always
written (x,y)
The intersection of the axes forms 4 Quadrants, labeled I, II, III
and IV going counter-clockwise from the top right-hand corner.
The characteristics of a point in each quadrant are as follows:
Quadrant I (+, +)
Quadrant II (-, +)
Quadrant III (-,-)
Quadrant IV (+, -)
Standard test ends here
Multiplication: 3.1 and 3.2
+*+=+
-*-=+
-*+=+*-=Multiplication is commutative
Division: 3.3
Same as multiplication
+÷+=+
-÷-=+÷-=-÷+=Division is not commutative
Distributive Property of Multiplication over Addition 4.2
A * (b + c) = ab + ac
Factor by finding the common factor, that’s the ‘a’. The other 2 are
the b and c.
Distributive Property of Multiplication over Subtraction 4.3
Same as above, except with subtraction
A(b-c) = ab - ac