CCSS: 6.SP.B.4, 6.SP.B.5, 7.SP.B.3, 8.SP.A.1, MP1, MP5, MP6

TEKS: 6.12A, 6.12B, 6.12C, 6.12D, 6.13A, 7.6G, 7.12A, 8.5C, 8.11A

Shining Light on the Holidays

Nothing says the holidays like lights. Whether they’re on your tree, in store window displays, or twinkling on the lawns and houses in your neighborhood, you’re bound to see them: thousands of beautiful, bright bulbs.

Before the 1900s, we used candles to light up our trees, menorahs, and other cultural displays. The biggest problem back then was fire. To avoid burning down the house, candles on trees were lit for only a few minutes, and people had buckets of sand and water on hand.

The switch to electric bulbs has reduced the number of fires, and means the lights can be left on for hours. But that can burn up a lot of energy—and cash. The costs vary depending on the types of lights used, the number used, and how long the lights are on. Some people have simple displays of a single twinkling wreath, but others lavishly light up their entire yard! The costs to power all those lights can be pretty steep.

To save on energy usage and cost, engineers have made lights called LEDs. They use far less energy and last longer than traditional incandescent lights. If you have a string of old lights, you can replace those bulbs with LEDs to save energy and money. And stores like Home Depot will give you coupons to purchase efficient lights after you trade in your string of old incandescent lights.

It’s fun to drive around looking for the best light display, but it’s also fun to think about what it takes to make that happen.  

Answer the following questions using the information in the charts and graphs above.

What’s the difference in height between a C9 bulb and a bubble light?

A) 1 inch
B) 1.5 inches

C) 2 inches
D) 2.5 inches

How many total watts are used to light a 150-foot rope light, a 9-foot garland, and 2 lighted reindeer with LEDs? 

A) 162 watts
B) 200 watts

C) 234 watts
D) 584 watts

What percent of an average adult’s holiday budget is spent on gifts for family, friends, and other categories combined? 

A) 68%
B) 71%

C) 74%
D) 78% 

About how many M5 light bulbs are equal to the height of one bubble light bulb?  

A) 2 bulbs
B) 5 bulbs

C) 7 bulbs
D) 8 bulbs

How many fewer watts are needed to light 5 wreaths with LEDs versus incandescent bulbs?

A) 20 watts
B) 55 watts

C) 79 watts
D) 85 watts

About how much did the average adult plan to spend on flowers and decorations combined last holiday season?

A) $81
B) $95

C) $105
D) $129

On average, a watt costs $0.0124. How much would you save with an 800-ft string of LEDs instead of incandescent lights, rounded to the nearest cent?

What is the median height of the bulbs in the graph? 

Write an equation to find the watts, w, used by a string of incandescent lights that is f feet long.  

Which type of graph is best to display the data showing the wattage for incandescent bulbs and LEDs? Explain your answer.

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