Download Adding Two Numbers With the Same Sign

Adding Two Numbers With the Same Sign Add their absolute values. Use their common sign as the sign of the sum.
Same sum
Same sign
Adding Two Numbers with Different Signs –
Subtract the smaller absolute value from the larger absolute value. Use the sign of the number whose
absolute value is larger as the sign of the sum.
Different difference
Sign of the “larger”
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We know 3 2 1
and
3 2 1
so
3 2 3 2
Subtraction is addition of the opposite.
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Multiplication is repeated addition.
We can write
2 2 2 2 = ______ × _______ = _______.
So similarly, 2 2 2 2 ______ × _______ = _______.
See rule 2 below.
Use a pattern to find the product of a negative and a negative.
22 12 02 12 22 See rule 1 below.
Multiplying Real Numbers
1. The product of two numbers with the same sign is a positive number.
2. The product of two numbers with different signs is a negative number.
Same sign +
Different signs -
Remember: The method for dividing fractions is to multiply by the reciprocal of the divisor.
a ÷b = a⋅
1
, where a and b are real numbers and b is not 0. What does this tell us about the rules for
b
dividing fractions?