~ 4.1 ~

Learning Targets

• I remember how to compute percentages.
• I can find dimensions on scaled copies of a rectangle.

Imagine you have a painting that is 15 feet wide and 5 feet high. To sketch a scaled copy of the painting, the ratio of the width and height of a scaled copy must be equivalent to 15:5. What is the height of a scaled copy that is 2 feet across?

We know that the height is 13 the width, so h = ⅓ ⋅ 2 or ⅔.

Sometimes ratios include fractions and decimals. We will be working with these kinds of ratios in the next few lessons.

There are many places that display flags of different sizes.

• Many classrooms display a U.S. flag.
• Flags are often displayed on stamps.
• There was a flag on the space shuttle.
• Astronauts on the Apollo missions had a flag on a shoulder patch.

1. Choose one of the four options and decide on a size that would be appropriate for this flag. Find the size of the union.
2. Share your answer with another group that used a different option. What do your dimensions have in common?

For each question, first estimate the answer and then compute the actual percentage.

1. What percentage of the flag is taken up by the union?
2. What percentage of the flag is red? Be prepared to share your reasoning.

*Hint* To find percent, divide your measurement by the total. Then multiply by 100.

FUN FACT:

The largest US flag, dubbed the "Superflag", was commissioned by Mr. Thomas "Ski" Demski. It measures 505 feet by 225 feet and weighs 3,000 pounds, takes 500 people to unfurl, and sets the world record for the Largest US Flag. "Ski" Demski had this flag made of cloth and sewn together in Pennsylvania (his home state) and delivered to him on Flag Day on June 14, 1992.

This is a photograph of Superflag hanging in front of Hoover Dam, taken on May 1, 1996. This flag was unfurled before the Olympic Torch was carried across Hoover Dam in conjunction with the 1996 Summer Olympic Games. Held up by three cables, one snapped just as the event finished!