Download 5-5 6th grade math

5-5
6th grade math
Solving Addition and Subtraction Equations
Objectives
• To solve equations involving fractions and
mixed numbers.
Why? To be able to solve more complicated
equations. .. The stepping stones to solving
Algebra problems.
California State Standards
• AF 1.1
: Write and solve one-step linear
equations in one variable.
• NS 2.0
: Calculate and solve problems
involving addition, subtraction, …
• NS 2.1: Solve problems involving addition,
subtraction, … of positive fractions and explain
why a particular operation was used for a
given situation.
Vocabulary
• Equations
– A number sentence stating that two expressions are equal.
• X – 26 = 85
• W + 41.8 = 55.9
* 4x = 16
* v/6 = 3.6
• Variables
– A letter used to stand for a number in an expression or
equation.
• 45 + x = 67
• Inverse Operations
– Two operations with an opposite effect. Addition and
subtraction are inverse operations. Multiplication and
division are inverse operations.
• 256x = 1024
256 ÷ 256 x = 1024 ÷ 256
x=4
How to Solve Addition Equations
½+x=¾
1. Undo the addition by
subtracting (½) from
both sides
2. Write the fractions
with their LCD
3. Solve
4. Simplify, if possible
½+x=¾
1. ½ - ½ + x = ¾ - ½
2. X = ¾ - 2/4
3. X = 1/4
How to Solve Subtraction Equations
m – 3  = 18 3/5
1. Undo the subtraction
by addition (3 2/3)
from both sides
2. Write the fractions
with their LCD
3. Solve
4. Simplify, if possible
m – 3  = 18 3/5
1. m – 3  + 3  = 18 3/5 + 3 
2. M = 18 9
15
3 10
+ 15
21 19/15 = 22 4/15
Try It!
1. n + 3/5 = 1
1. n = 2/5
2. 2  = x + 2 1/18
2. x = 5/18
3. a – 5/6 = 1/16
3. a = 43/48
4. y + 2 1/18 = 3 ¼
4. y = 1 7/36
Here’s How It Works…
1. n + 3/5 = 1
1) n + 3/5 – 3/5 = 1 – 3/5
5/5 – 3/5 =
2/5
2. 2  = x + 2 1/18
2) x + 2 1/18 – 2 1/18= 2  - 2 1/18
x = 2 6/18 - 2 1/18
x = 5/18

3) a – 5/6 = 1/16
3) a – 5/6 + 5/6 = 1/16 + 5/6
a = 3/48 + 40/48
a = 43/48
4) y + 2 1/18 = 3 ¼
4) y + 2 1/18 – 2 1/18 = 3 ¼ - 1/18
y = 3 9/36 – 2 2/36
y = 1 7/36
Objectives Review
• To solve equations
involving fractions
and mixed numbers.
• Why? You can solve
more complicated
equations. .. These are
the stepping stones to
solving Algebra
problems (your future
career in education).
Independent Practice
• Complete problems
6-11
• Copy original
problem first.
• Show ALL work!
• If time, complete Mixed
Review: 12-18.
• If still more time, work
on Accelerated Math