The concept of negative numbers originated in India,
as did the concept of "0". Let us look at this idea.
Imagine the temperature is minus 8
degrees (or
as we say 8 degrees below zero) and then we
receive an
inflow of heat from the south. The temperature
goes
up 6 degrees (not 6 degrees above zero but just
6
degrees warmer than it was). What is the
temperature now?
minus 8 degrees is written
as -8 degrees
positive 6 degrees is written
as +6 degrees
the new temperature
is -2
degrees
When we add numbers with different signs,
find the
difference between the number and give the
answer the
sign of the larger number.
For
example
-9 or -7
+4 +8
-5 +1
The + and - are call positive and negative
signs and do not indicate the arithmetic operations of addition and
subtraction.
add the
following 1. -14
+17 answer
When you add numbers with the same signs find the total of the digits and
give
the answer the common sign. examples +3 + (+5) = +8 this
example would be written 3 + 5 = 8 without the + signs in front of
the numbers.
example -7 + (-4) = -11
Remember that a number with a positive sign (+) tells that the number is greater than 0. (numbers with no signs are considered to be positive
numbers)
A number with a negative sign (-) tells us that the number is less than 0.