DIRECTED NUMBERS

DEFINITION OF A DIRECTED: A directed number is one on which a negative or positive sign is attached.We have four arithmetic operations which include addition(+), subtraction(-), multiplication(x), and division(➗). It should be noted here that an operational sign especially for addition or subtraction is different from the directional sign.The operational sign between two numbers must be centralized while a directional sign is written slightly below or above. For example 7+-5 , 6--4
              
                        ARITHMETIC OPERATIONS ON DIRECTED NUMBERS
ADDITION: There are two basic rules both depending on the sign attached to the numbers.
        i)-if the two directed numbers to be added have the same sign, simply add the absolute values and maintain the sign on your answer. eg. a) 6+7=13
                                 b)-3+-5=-8
        ii)-if the two numbers to be added have different signs, subtract the absolute value of the smaller number from the absolute value of the bigger one and maintain the sign of the bigger number.
                             eg. a) 6+-9=-3
                                   b) -6+9=+3
                                   c) -28+11=-17
                                   d) -11+28=+17
Exercise
a) 7+6=
b) -3+-5=
c) -61+-4=
d)-3+-4+-5=
e) -6+-4+10=

SUBTRACTION: Subtraction is the reverse of addition.It can be converted to addition and two basic rules applied as explained below.
   i-To subtract two directed numbers, we change the operational (-) sign to (+) sign and reverse the direction sign of the second number.We can then apply the two basic rules of addition
   eg. a) 6-4= 6+-4=2
         b) -6-4=-6+-4=-10
         c) 6--4=6+4=10
         e) -6--4=-6+4=-2
Exercise
a)7-5=
b) -6-8=
c) -17--5=
d)  50--10=
e) -9-13=
f) -4--6-10=

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