Scale Drawings & Double Number Lines

Have you ever tried reorganizing your room and used a scale drawing to try out different arrangements?
The double number line is one way to figure out the proportion of the actual size compared to the scale size.   As shown in the number line the equivalence of the sizes is shown in fraction form, or on opposite sides of the number line.  The larger measurement is on the bottom and the smaller measurement is on top.  In the problem below a room has a width of 3 meters and a length of 2.6 meters.  One way to scale this down would be to convert 3 meters into 300 cm, and then divide 300 cm. by 20 to get 15 cm.

0                                  5                                  10                                15

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0                                  100                              200                              300

The furniture in the chart can be converted from its actual size to a scale size by using the double number line. Another strategy is simply to use the equation for the rate.
(Actual Size ÷ 20 = Scale Size) Try to find the scale measurements for the furniture in the chart. Here’s a video link on Scale Helicopters from Khan Academy.
Enjoy :)

Furniture	Actual width/length (cm)	Scale width/length  (cm)
Dresser	80 cm / 30 cm
Chair	50 cm  / 50 cm
Bed	100 cm /170 cm
Desk	110 cm / 60 cm