# MATH 84 – SUBTRACTING INTEGERS ```MATH 84 – SUBTRACTING INTEGERS!
Partner #1: ___________________________________________
Partner #2: ____________________________________________
Partner #3:____________________________________________
Use the number lines and arrows to show the following problems
and answers. Recall that when we add a positive integer we go to
the right on the number line. When we add a negative integer we
go to the left on the number line. However, when we subtract a
positive number we go to the left on the number line, and when we
subtract a negative number, we go to the right on the number line!
#1) 5 – 3 =
#2) 5 + (-3) =
#3) 5 – (-3) =
#4) 5 + 3 =
#5) –4 – 2 =
#6) –4 + (-2) =
#7) 0 – 4 =
#8) 0 + (-4) =
#9) –3 – 5 =
#10) –3 + (-5) =
#11) 4 – (-1) =
#12) 4 + 1 =
The above problems (1 and 2), (3 and 4) etc. show that any
subtraction problem can be rewritten an addition problem and the
results are the same! We can use the algebraic rule
x – y = x + (- y) to change any subtraction problem into an addition
problem with integers.
Here are the steps.
1) Keep the first integer the same.
2) Change the subtraction operation to addition.
3) Change the second integer to its opposite.
4) Then us the rules for addition!
Change the following subtraction problems to addition problems
using the rule x – y = x+ (-y) and then find your answers!
#13) –42 – (-16) =
#14) –88 – 22 =
#15) 66 – (-66) =
#16) 92 - 64 =
#17) Find the difference between –45 and 16.
#18) Subtract –62 from –38.
#19) –44 – 22 – (-66) =
#20) –37 – [-42 – (-20)]
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