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2-6 Addition Equations
Warm Up
Problem of the Day
Lesson Presentation
Lesson Quizzes
2-6 Addition Equations
Warm Up
Determine whether each value is a solution.
1. 86 + x = 102 for x = 16
yes
2. 18 + x = 26 for x = 4
no
3. x + 46 = 214 for x = 168 yes
4. 9 + x = 35 for x = 26
yes
2-6 Addition Equations
Problem of the Day
After Renee used 40 m of string for her kite
and gave 5 m to her sister for her wagon,
she had 8 m of string left. How much string
did she have to start with?
53 m
2-6 Addition Equations
Sunshine State Standards
MA.6.A.3.2 Write [and] solve…one-step
linear equations…
2-6 Addition Equations
Vocabulary
inverse operations
2-6 Addition Equations
h + 14
82
h
?
h + 14
h
82
68
The equation h + 14 = 82 can be
represented as a balanced scale.
To find the value of h, you need h
by itself on one side of the scale.
To get h by itself, first take away
14 from the left side of the scale.
Now the scale is unbalanced.
To rebalance the scale, take away
14 from the other side.
2-6 Addition Equations
Taking away 14 from both sides of the scale is
the same as subtracting 14 from both sides of
the equation.
h + 14 = 82
–14 –14
h = 68
Inverse operations undo each other.
Addition and subtraction are inverse
operations. If an equation contains addition,
solve it by subtracting from both sides to
“undo” the addition.
2-6 Addition Equations
Additional Example 1A: Solving Addition Equations
Solve the equation. Check your answer.
x + 87 = 152
x + 87 = 152
– 87 – 87
87 is added to x.
Subtract 87 from both
sides to undo the addition.
x = 65
Check x + 87 = 152
?
Substitute 65 for x in the
equation.
65 + 87 = 152
?
152 = 152  65 is the solution.
2-6 Addition Equations
Additional Example 1B: Solving Addition Equations
Solve the equation. Check your answer.
72 = 18 + y
72 = 18 + y
–18 –18
54 =
y
Check 72 = 18 + y
?
72 = 18 + 54
?
72 = 72 
18 is added to y.
Subtract 18 from both
sides to undo the addition.
Substitute 54 for y in the
equation.
54 is the solution.
2-6 Addition Equations
Check It Out : 1A
Solve each equation. Check your answers.
u + 43 = 78
u + 43 = 78
- 43 = - 43
u
= 35
2-6 Addition Equations
Check It Out : 1B
Solve each equation. Check your answers.
20 = 6 + n
20 =
-6 =
14 =
6+n
-6
n
2-6 Addition Equations
Check It Out : 1C
Solve each equation. Check your answers.
78 + w = 87
78 + w = 87
- 78
- 78
w=
9
2-6 Addition Equations
Check It Out : 2A
For each exercise, write an addition equation.
Then solve the equation.
Sandy is thinking of a number. When 33 is added
to the number, the sum is equal to 55. What
number is Sandy thinking of?
x + 33 = 55;
x = 22;
Sandy is thinking of the number 22.
2-6 Addition Equations
Check It Out : 2B
For each exercise, write an addition equation.
Then solve the equation.
SheiKra is a roller coaster at Busch Gardens in
Tampa, Florida. You must be 54 inches tall to ride
SheiKra. Lisa is 5 inches short of this height
requirement. Find the height h of Lisa in inches.
h + 5 = 54;
h = 49;
Lisa is 49 inches tall.
2-6 Addition Equations
Additional Example 2: Social Studies Application
Johnstown, Cooperstown, and Springfield are located
in that order in a straight line along a highway. It is
12 miles from Johnstown to Cooperstown and 95 miles
from Johnstown to Springfield. Find the distance d
between Cooperstown and Springfield.
distance between
Johnstown and
Springfield
=
95
=
95 = 12 + d
–12
–12
83 =
d
distance between
Johnstown and
Cooperstown
12
+
distance between
Cooperstown and
Springfield
+
d
12 is added to d.
Subtract 12 from both sides to undo
the addition.
It is 83 miles from Cooperstown to Springfield.
2-6 Addition Equations
Check It Out : 2C
For each exercise, write an addition equation. Then
solve the equation.
Patterson, Jacobsville, and East Valley are located
in that order in a straight line along a highway. It is
17 miles from Patterson to acobsville and 35 miles
from Patterson to East Valley. Find the distance d
between Jacobsville and East Valley.
17 + d = 35;
d = 18;
It is 18 miles from Jacobsville to East Valley.
2-6 Addition Equations
Check It Out : 2D
For each exercise, write an addition equation. Then
solve the equation.
In Olympic archery, competitors use stabilizers to
help balance the bow. The main stabilizer is at most
36 inches in length. This is 7 inches more than its
minimum length. What is the minimum length of
the main stabilizer?
x + 7 = 36;
x = 29;
The minimum length is 29 inches.
2-6 Addition Equations
Lesson Quizzes
Standard Lesson Quiz
Lesson Quiz for Student Response Systems
2-6 Addition Equations
Lesson Quiz
Solve each equation.
1. x + 15 = 72
x = 57
2. 81 = x + 24
x = 57
3. x + 22 = 67
x = 45
4. 93 = x + 14
x = 79
5. Kaitlin is 2 inches taller than Reba. Reba is 54
inches tall. How tall is Kaitlin?
56 inches
2-6 Addition Equations
Lesson Quiz for Student Response Systems
1. Solve the equation x + 26 = 75.
A. x = 39
B. x = 49
C. x = 59
D. x = 101
2-6 Addition Equations
Lesson Quiz for Student Response Systems
2. Solve the equation 71 = y + 47.
A. y = 24
B. y = 28
C. y = 108
D. y = 118
2-6 Addition Equations
Lesson Quiz for Student Response Systems
3. Solve the equation z + 37 = 65.
A. z = 102
B. z = 92
C. z = 38
D. z = 28
2-6 Addition Equations
Lesson Quiz for Student Response Systems
4. Solve the equation 76 = x + 39.
A. x = 27
B. x = 37
C. x = 95
D. x = 115
2-6 Addition Equations
Lesson Quiz for Student Response Systems
5. Steven has 9 more music CDs than Carol.
Steven has 25 music CDs. How many music
CDs does Carol have?
A. 7 music CDs
B. 9 music CDs
C. 16 music CDs
D. 25 music CDs