Lesson 17The Stock Market

Learning Goal

Let’s learn about the Stock Market.

Learning Targets

I can solve problems about the stock market using rational numbers and percentages.

Warm Up: Revisiting Interest and Depreciation

Problem 1

Lin deposited $300 in a savings account that has a 2% interest rate per year. How much is in her account after 1 year? After 2 years?

Problem 2

Diego wants to sell his bicycle. It cost $150 when he bought it but has depreciated by 15%. How much should he sell it for?

Activity 1: Gains and Losses

Problem 1

Here is some information from the stock market in September 2016. Complete the table.

company	value on day 1 (dollars)	value on day 2 (dollars)	change in value (dollars)	change in value as a percentage of day 1 value
Mobile Tech Company	$107.95$	$111.77$	$3.82$	$3.54 %$
Electrical Appliance Company		$114.03$	$2.43$	$2.18 %$
Oil Corporation	$26.14$	$25.14$		$- 3.83 %$
Department Store Company	$7.38$	$7.17$
Jewelry Company		$70.30$		$2.27 %$

Problem 2

Which company’s change in dollars had the largest magnitude?

Problem 3

Which company’s change in percentage had the largest magnitude?

Activity 2: What Is a Stock Portfolio?

A person who wants to make money by investing in the stock market usually buys a portfolio, or a collection of different stocks. That way, if one of the stocks decreases in value, they won’t lose all of their money at once.

Here is an example of someone’s stock portfolio. Complete the table to show the total value of each investment.
name
price (dollars)
number of shares
total value (dollars)
Technology Company
$107.75$
$98$
Airline Company
$133.54$
$27$
Film Company
$95.95$
$135$
Sports Clothing Company
$58.96$
$100$

name	price (dollars)	number of shares
Technology Company	$107.75$	$98$
Airline Company	$133.54$	$27$
Film Company	$95.95$	$135$
Sports Clothing Company	$58.96$	$100$

Here is the same portfolio the next year. Complete the table to show the new total value of each investment.

company	old price (dollars)	price change	new price (dollars)	number of shares
Technology Company	$107.75$	$+ 2.43 %$		$98$
Airline Company	$133.54$	$- 7.67 %$		$27$
Film Company	$95.95$		$87.58$	$135$
Sports Clothing Company	$58.96$	$- 5.56 %$		$100$

Did the entire portfolio increase or decrease in value over the year?

Activity 3: Your Own Stock Portfolio

Your teacher will give you a list of stocks.

Select a combination of stocks with a total value close to, but no more than, $100.
Using the new list, how did the total value of your selected stocks change?