september 12, 2014

September 12, 2014

Today:Vocabulary

Equations, Equations, Equations

Review for Tuesday’s test

Review & Complete Yesterday’s

Class Work

A few more students registered & added a coach @ Khan Academy yesterday. Thank you. Next week’s topics posted on-line this weekend and on the board Monday.

You can sign up for lunch or after school before the end of class.

≈ 10 people took advantage of the extra credit opportunity posted each Tuesday at the v6math site. Well done to you folks.

More help available at the v6math site: This year’s first volume of the Algebra Connections newsletter is out. It’s only 2 pages and packed with the things you need to know for the Unit we’re working on now. Great study guide for Tuesday’s test.

1. Working with Negative Numbers:

The symbol for negative numbers ( - ), means “The Opposite of”

All positive numbers could be written with a ‘+’ in front of them, but the sign was left off as the number system developed. So, numbers with a sign are the ‘opposite’ of whatever number follows.

- 4 - ( - 4) 10 – 4 is really 10 + the opposite of 4. All subtraction is the addition of the opposite.

When you add any number and its opposite, you get…?

Vocabulary

Warm-Up: Equations

Because solving equations is the most performed task in algebra, the earlier you get comfortable with equations, the easier the course will be for you.Let’s start with a problem we can answer without algebra:A. The sum of two consecutive numbers is nine. What are the numbers?Those not skilled in the way of the equation will want to write: x + 1 = 9. Translated, this equation is 5 = 9

4 + 5 = 9

The correct translation, of course, is: x + (x + 1). The equation now states that 4 + 4 + 1 = 9. Yes.Values of all other unknowns in a problem are shown as the relationship between the value and our assigned variable. Four is our ‘x’. Five is written showing its relationship to 4. When you have 5, you have 4.....plus 1.

This was the common mistake from the writing equation question from yesterday’s

class work.

1. Find the perimeter of the rectangle:

Warm-Up: Formulas & Equations

14’6’

2. Find the area of the rectangle: 3. That was basic arithmetic. Now let’s use algebra to solve this one: Write an equation to find the width of the rectangle if the length is 60 ft. and the perimeter is 180 ft.

L =60’

P = 40’

4. What if…, the area of the rectangle is 68 ft. and the width is 4ft. What is the length?

A = 68’

W = 4’

P = 180’A = 84’

1. As the head pastry chef, you make $7.00/hr. So far you have earned $42.00. Which of the following equations is the algebraic model for this situation?

Warm-Up: Writing Equations to Solve Problems

P = 4S

4(3x – 10) = 3212x - 40 = 32

12x = 72

The length of each side is 6

Warm-Up: Equations & Translating

1. Buck has $20 more than Roger. Together they have $60. How much does each one have?

2. Peter has $6 more than Meg. Chris has $18 more than Peter. They have $84 all together. How much does each one have? 3. The sum of 3 consecutive numbers is 87. What are the three numbers?

Key Concepts: Always Assign the variable to the smallest, least, lightest, shortest, etc. Every other number is shown by its relationship to the variable.

4. Billy Bob worked 6 hours less than Sally May. Together they worked 64 hours. How many hours did each work?

Complete yesterday’s

class work