ADDING AND SUBTRACTING RATIONAL NUMBERS RATIONAL NUMBER ADDING
ADDING AND SUBTRACTING RATIONAL NUMBERS
RATIONAL NUMBER:
ADDING AND SUBTRACTING We can use the same rules we found for integers for rational numbers �Adding Rule 1: If the signs are the same Add and keep the same sign �Adding Rule 2: Different signs Subtract and use larger sign �Subtracting Rule: Keep-Change
FRACTIONS Let’s review �Example 1: �Try this one: OR I could use Keep-Change!
MORE FRACTIONS Problem 1: Remember: We subtract to find our answer because we are battling our zero pairs! Which fraction has a bigger absolute value? So the sign of our answer is positive!
TRY THIS ONE: Problem 2: Remember we want to wait until we have a common denominator before we decide which fraction has a bigger absolute value.
A COUPLE MORE: Problem 3: Subtraction Keep-Change! Problem 4: Keep-Change!
MIXED NUMBERS Problem 1: Remember this only works when they have the SAME S IGN! Problem 2: Whoa! That looks easy! Let’s think a bout pizza…
MORE MIXED NUMBERS
LET’S TALK ABOUT DECIMALS They wo rk the sa me way integers as and frac tions! Ju follow y st our addi ng and subtract ing integ er rules! Keep-Change
PROPERTIES Commutative Property of Addition: Numbers can be added in any order. � Example: 5+3=3+5 Associative Property of Addition: Numbers can be grouped in any way. � Example: (7+3) + 5 = 7 + (3+5) Identity Property of Addition: The sum of any number and zero is that number. � Example: 18 + 0 = 18
MORE WITH PROPERTIES Identity Property of Addition Associative Property of Addition Commutative Property of Addition
ADDING AND SUBTRACTING RATIONAL NUMBERS PRACTICE
- Slides: 13