8. If I took one block away from the left
side, what would I have to do to keep
the scale from tipping?
9. If I added 6 more apples to the right
side, how could I keep the scale from
tipping?
10. To keep an equation
equal, we must do
exactly the same thing to
each side of the
equation. If we add a
number to one side, we
must add that same
number to the other side
and vice versa.
19. Example 1 (bar model)
m + 18 = 34
m
18
34
Look for variable
Do the inverse
What number does m represent?
m = 16
Substitute in m
16
18
34
16 + 18 = 34
34 = 34
Solution is correct!
20. Example 1
m + 18 = 34
-18 -18
m = 16
Do the inverse
m + 18 = 34
16 + 18 = 34
34 = 34
substitute in m
Look for variable
Write what m is
Solution is correct!
22. Example 2
68 = y + 43
-43
-43
Look for variable
25 = y
68 = y + 43
68 = 25 + 43
68 = 68
Write what y is
Do the opposite
Plug in y
Solution is correct!
23. Example 3
t - 14 = 22
+ 14 +14
t = 36
Do the inverse
t - 14 = 22
36 - 14 = 22
22 = 22
Substitute in t
Look for variable
Write what t is
Solution is correct!
