## Welcome to Math 20!

Our **syllabus** describes the class calendar, homework, grading, and other important information.

Mastering new math ideas ultimately involves changing how we think and practicing thinking critically. These have been called the two keys to student success.

Therefore the process of learning our math topics is like a chair that stands on four legs: turning lectures into helpful lecture notes, dilligently doing both "prompt" and "enough" homework problems, developing good test-taking techniques, and rehearsing careful step-by-step work on practice tests. Neglecting any of these four is dangerous! Please do not demonstrate such recklessness. Successful students make time for all four.

## Online Lecture Notes

### Arithmetic

**Concepts:**
Understanding Division,
Factors,
Rounding,
Estimating,
Exponents,
The Perils of PEMDAS,
Terms,
Negative Numbers

**Skills:**
Divisibility Rules,
Finding Factors,
Decimal Point Scoots,
One-Step Equations,
Shoes and Socks

Review Problems

Homework

### Fractions

**Concepts:**
Desired Denominators,
Fraction Multiplication and Division,
The Six Step Problem Solving Method

**Skills:**
Addition and Subtraction,
Subtracting Mixed Numbers,
Changing Fractions to Decimals,
Changing Decimals to Fractions

Review Problems

Homework

### Ratio, Rate, and Proportion

**Concepts:**
Four Definitions

**Skills:**
Writing and Simplifying Ratios,
Multiply in an X Shape,
Proportions with Variables,
Word Problems,
Scaling

Homework

### Percent

**Concepts:**
As a Rating Scale,
Shortcuts

**Skills:**
Percents, Decimals, and Fractions,
Percent Sentences,
Word Problems,
Simple Interest,
Percent Change,
Approaching Formulas,
The One Plus Trick,
The Fraction Trick

Homework

### Measurement

**Concepts:**
Measurement Units,
History,
One Step Conversions,
Conversion Rates,
Parts of a Gallon,
Square Roots

**Skills:**
Unit Analysis,
Temperature Conversions,
More About SI Prefixes

Homework

### Geometry

**Concepts:**
Perimeter,
Area Formulas,
Square Units,
Pi

**Skills:**
Polygon Area Puzzles,
Measured Sides,
Problem Solving Steps,
Circle Puzzles

Homework

## Tests

Test 1 — Arithmetic and Fractions (Chapters 1 to 4)

Test 2 — Ratio and Percent (Chapters 5 and 6)

Test 3 — Measurement and Geometry (Chapters 8 and 9)

Test 4 — Final Exam