**The use of letters in algebra**

**1. The use of letters**

- In general, an algebraic expression involves numbers and letters that are connected with operation symbols such as “+”, “-”, “x” and “/”
- In 10 + 8n, we call n a
**variable**and 10 + 8n an**algebraic expression**

**2. Basic notation in algebra**

- In algebra, there are rules for writing algebraic expressions. The operation symbols “+”, “-”, “x”, “/” and “=” have the same meanings in both algebra and arithmetic.
- Add a to b: sum = a + b = b + a
- Subtract c from d: difference = d – c != c -d
- Multiply g by h: product = g x h = h x g = gh
- Divide x by y where y != 0: quotient = x/y

**3. Exponential notation**

- Teach in the class on white board

**4. Simplify algebraic expressions**

- Teach in the class on white board

**5. Home Work:**

- Handout: two pages
- Workbook:
- page 15: 1, 2
- page 16: 6, 7, 8, 9, 10