Solving equations:

- (5 min) Mental Math
- Start with 77, add 23, then divide by 10 [10]
- How many inches are there in 4 feet? [48]
- Multiply 3.6 by 10 [36]
- What is 1/2 times 3/4? [3/8]
- What is the decimal for 86 divided by 10? [8.6]

- (5 min) Review of homework #12 (<= 3 problems)

- (5 min) Discuss order of operations:

- Pass out the "Order of Operations" handout.
Follow the discussion in the handout. Go through the
examples on the handout.

- Do these examples
*(ask students what operations to do first)*:

- 3 + 4 x 6 - 9 = [18]

- ( 3 + 4 ) x 6 - 9 = [33]

- 8 + 6 / 2 + 4 = [15]

- ( 8 + 6 ) / 2 + 4 = [11]

- 3 + 4 x 6 - 9 = [18]

- Pass out the "Order of Operations" handout.
Follow the discussion in the handout. Go through the
examples on the handout.
- (10 min) Discuss equation solving. Follow the handout. Use this
discussion:

"Remember in the second grade when your teacher asked you to fill in the box in a problem like this:"

4 + = 10

"In algebra, all we do is use a letter, like 'x' instead of a box:"

4 + X = 10

- Do these examples:

- 6 - x = 2 Ask:"six minus what number gives you 2?"[x =4]

- x + 15 = 25 Ask:"what number plus 15 is 25?"[x = 10]

- 4x = 8 Ask:"4 times what number is 8?"[x = 2]

- x/3 = 3 Ask:"what number divided by 3 is 3?"[x = 9]

- 6 - x = 2 Ask:"six minus what number gives you 2?"[x =4]
- Show students how to solve problems that have 2 terms on one
side, by covering up the term containing x, solving for the whole
term, then finding x:

Examples:

Equation Step 1:

Cover up

boxed termStep 2:

Solve for

boxed termStep 3:

Solve for value

in box3x + 1 = 7 3x = 6, so

x = 2x/2 - 1 = 3 - 1 = 3 x/2 = 4, so

x = 8