## Real World Applications – Algebra I

### Topic

How can we identify specific places on a map?

### Student Exploration

Below is a screen shot of a part of San Francisco, California.

We’re going to practice plotting points and writing ordered pairs based on this map.

- 1. First, we need our horizontal and vertical axes. Draw your \begin{align*}x-\end{align*}axis on \begin{align*}24^{th}\end{align*} Street, and draw your \begin{align*}y-\end{align*}axis on Mission Street. Every unit on the \begin{align*}x-\end{align*}axis will be one horizontal block, and every unit on the \begin{align*}y-\end{align*}axis will be one vertical city block. Draw and label your tick marks on each axis.
- 2. What is at the origin? Label that point on your map.
- 3. What is the ordered pair for where “El Capitan” is located?
- 4. City College of San Francisco is located on Valencia St. between \begin{align*}22^{nd}\end{align*} and \begin{align*}23^{rd}\end{align*} Avenues. Mark a point on this map and label with the ordered pair and the name of the college.
- 5. John O’Connell High School is the brown colored block located between Folsom St, Harrison St, \begin{align*}19^{th}\end{align*} St and \begin{align*}20^{th}\end{align*} St.How would you describe this point as an ordered pair?
- 6. What’s easier about describing specific places on a map using ordered pairs? What’s more challenging about using a coordinate system?

### Extension Investigation

- 7. Create a map of the city or town you live in. Determine where your \begin{align*}x-\end{align*} and \begin{align*}y-\end{align*}axes are and draw them on your map.
- 8. Draw and label some of the landmarks you feel are important on your map. Label the ordered pairs.
- 9. Draw and label the other schools on your map. Include all elementary schools, preschools, even colleges!
- 10. Draw and label all of the liquor stores on your map. You might want to mark these landmarks in a different color or with a different symbol.
- 11. What similarities can you make about the number of and locations of all of the schools in the area with the number of and locations of all of the liquor stores? Do you see any differences?

### Resources Cited

### Connections to other CK-12 Subject Areas

- Geometry & Algebra (Pythagorean Theorem and its Converse)
- Algebra (Distance Formula; Midpoint Formula)