Transcript integers_-_adding_

Interesting Integers!
Adding
What You Will Learn
Rules for adding integers.
A method for proving that a rule is
true
Are you ready??
Integer Addition Rules

Rule #1 – If the signs are the same,
pretend the signs aren’t there. Add
the numbers and then keep the same
sign.
9 + 5 = 14
-9 + -5 = -14
Solve the Problems
-3 + -5 = -8
11
4 + 7 =
7
 (+3) + (+4) =
 -6 + -7 = -13
 5 + 9 = 14
 -9 + -9 = -18

1.
2.
3.
4.
8 + 13 =
–22 + -11 =
55 + 17 =
–14 + -35 =
Integer Addition Rules

Rule #2 – If the signs are different
pretend the signs aren’t there.
Subtract the smaller from the larger
one and put the sign of the one with
the larger absolute value in front of
your answer.
-9 + +5 =
9 - 5 = 4 Answer = - 4
Larger abs. value
Solve These Problems
3 + -5 = 5 – 3 = 2
 -4 + 7 = 7 – 4 = 3
 (+3) + (-4) = 4 – 3
 -6 + 7 = 7 – 6 = 1
 5 + -9 = 9 – 5 = 4
 -9 + 9 = 9 – 9 = 0

-2
3
=1
1
-4
0
-1
Signs same – add and keep.
Different – just subtract.
Keep the sign of the bigger
one – then it will be exact.
(sing to the tune of row row
row your boat)
1.
2.
3.
4.
–12 + 22 =
–20 + 5 =
14 + (-7) =
–70 + 15 =
One Way to Add Integers Is
With a Number Line
When the number is positive, count
to the right.
When the number is negative, count
to the left.
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
One Way to Add Integers Is
With a Number Line
+3 + -5 = -2
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
One Way to Add Integers Is
With a Number Line
+6 + -4 = +2
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
One Way to Add Integers Is
With a Number Line
+3 + -7 = -4
+
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
-
One Way to Add Integers Is
With a Number Line
-3 + +7 = +4
-
-6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6
+
Ready to practice?

Let’s go out in the hallway and use a
big number line to solve some
problems.

Working with your shoulder partner,
solve the problems on the paper. Use
the sage and scribe method – person 1
tells partner what to do while person 2
writes (praising or correcting). Then
switch roles for next problem. Follow
this procedure until you have the circled
problems in column 1 completed.
Homework:
pg 61 32-46 evens
Read pages 63 and 64