Ratios compare two different numbers, such as speed over distance. Proportions compare the difference between two different numbers of the same objects, such as marbles or books. There are many activities that help teach your students about these sometimes difficult to understand ideas and make the concepts easier to understand.
Body Proportion
Several parts of the body that are laid out in specific proportions. For example, the eyes are always situated in the middle of the face. Your foot is almost exactly the same length as your arm from wrist to elbow. Hand out a worksheet with these and more proportions printed on the front. Give each student a tape measure or ruler and 10 to 15 minutes to measure out these proportions on their body to verify their accuracy. Collect their work and post it on the bulletin board. The Promethean Planet website is a rich source of body proportion facts.
Skillwise Numbers
The BBC website has an online activity, Skillwise to teach your students form ratio formulas. The game displays a series of black and red marbles to the right side of the screen. The numbers of the marbles vary and are randomly generated with each new game. The game asks the students to formulate the ratio between the two marbles.
Students do this by placing the number of red marbles in the first text box and the number of black marbles in the second box. For example, if there were six red marbles and 10 black marbles, they would enter "6" and "10" into the correct boxes and press "enter." The game will verify the score and generate a new problem endlessly.
Travel Game
Teach your students about the ratio between speed and distance by using this activity. Your students must plan a trip to a specific city far from your home town. They can pick any town they like as long as they know the distance between the two towns. Students must plan how much gasoline they are going to use while on the trip. Student's can choose from three cars with varying gas mileages.
Students must figure out how many gallons of gas they must use to get to their town. They must also find out how long it will take them to get there if they obey a speed limit of 55 miles per hour. Check their calculations when they're done.
Quiz Show
Split your class up into two equal teams. The teams should appoint a leader to answer for them. Give the leader a small bell to ring to answer questions. Draw a proportion or ratio problem on the board. For example, if a car traveled 600 miles in 10 hours, how fast was it driving if its speed never changed? The first team to ring the bell gets 10 seconds to answer the question.
Give the team 10 points for answering the question first. Give the other team five points if they answer after the other team has failed to answer correctly. Include hands-on activities to keep your students engaged in the game. Hands-on activities can include finding the proportion between two different water jugs.
