Transcript Add Integers … Or Perhaps a Music Lesson?

IWBAT add integers.
Integer – any positive or
negative number, excluding
fractions, decimals, or percents.
But I don’t know how
to add integers!!! I
think that I am going
to …
No vorries children!
Adding integers is
not that different
from adding whole
numbers.
There are 3 ways that I use to add
integers:
1.)
Number Line
2.) Counters
3.) Song
To use the number line, follow these steps:
1.)
Start at the point of the first number
2.)
Then do one of two things:
a)
If the second number is positive,
go to the right the number of spaces
b)
If the second number is negative, go to
the left the number of spaces
Simplify: -3 + 7
-3
Move the point 7
spaces to the RIGHT
-5 -4 -3 -2 -1 0
1
2
3
4
4
5
6
3  7  4
7
8
9
Simplify: 4 + (-5)
Move the point 5
spaces to the LEFT
4
-1
-5 -4 -3 -2 -1 0
1
2
3
4
5
6
4  (5)  1
7
8
9
Simplify: -5 + 2
Move the point 2
spaces to the RIGHT
-5 -3
-5 -4 -3 -2 -1 0
1
2
3
4
5
6
5  2  3
7
8
9
To use the counters method, follow these steps:
1.)
Make a T-Chart
2.)
Use “+” signs to represent the positive number and “-”
to represent the negative number
3.)
Cross out every “+” that you have a “-” for
4.)
Count what you have left. That is your answer. If you
have more “+” left, your answer is positive; if you have
more “-” left, your answer is negative.
Simplify 9 + (-5)
9
-5
+
+
-
-
+
+
-
-
+
+
+
+
-
+

9  (5)  4
Simplify -8 + 3
-8
3
-
-
+
-
-
+
-
-
-
-

+
8  3  5
Simplify -3 + 7
-3
-
-
7
+
+
+
+
+
+
+

3  7  4
A word of
So if you have bigger
warning!!!!
numbers (which you
The number line
will), you need to
and counters
use the next
methods only work
method:
with small
THE SONG
numbers!!
To add integers, simply sing this song to the tune of Row,
Row, Row, Your Boat:
Simplify
-32 + 41
32  41  9
Simplify
-21 + 14
21 14  7
Simplify
-15 + (-20)
15  (20)  35
EXIT TICKET
1.
(–2) + (–9) + 18
2.
(–25) + 5 + –11
3.
14 + –3 + –8