BGCSE CORE
DIRECTED NUMBERS

Numbers can either be positive or negative. The name directed number comes from thinking of a number line. The sign tells which direction from 0 on the number line the number lies: positive numbers on the right and negative numbers on the left. 
Brackets are, at times, put around negative numbers to make them easier to read, e.g. (-2). Sometimes a '+' or '-' sign is written in front of the number. Both methods are used and you need to be happy using both. If a number is positive, the + is usually missed out before the number. So 3 is really (+3) or +3.

addition and subtractioN

If signs are the same (+), (+) OR (-), (-),you ADD and keep the same sign.
  • Thus +2 +2 = +4 and -5 -5 = -10
If signs are different (+), (-) OR (-), (+), you SUBTRACT and keep the sign of the LARGER number.
  • Thus  +2 -5 = -3 and -5 +4 = +1

another way

Two like signs become a positive sign
​Eg:   7−(−5) 
      = 7 + 5
      = 12
Two unlike signs become a negative sign
​​Eg:     8 +(−4)
        =  8 − 4  
​        = 4

MULTIPLICATiON AND DIVISION
  • If two positive numbers OR two negative numbers are multiplied together or divided, the answer is positive.
    • Thus 2 x 4 = 8 and 10 ÷ 2 = 5
    • Thus (-2) x (-4) = 8 and (-10) ÷ (-2) = 5
  • If a positive and a negative number are multiplied or divided, the answer is negative.
    • Thus (-2) x 4 = (-8) and 10 ÷ (-2) = (-5)

ACTIVITIES

LEVEL D WORKSHEETS
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WORKSHEETS
Addition & Subtraction
POWERPOINT

Understanding Negatives