Measure for Treasure
X marks the spot on drawn-to-scale classroom maps
- Grades: 3–5, 6–8
Treasure seekers have always known that the best way to find a cache of gold doubloons is to use a map — preferably one designed by an authentic pirate. But these days, good treasure maps are hard to come by. No problem. Your class can still experience the thrill of tracking and locating hidden booty, even in school! Help grades four through six students work together to prepare for a treasure hunt that uses math, map, and measurement skills.
Using one or more sample maps, take about 15 minutes to review four of their common features with your class: title, compass rose, map key, and scale. Point out how the title identifies the geographical area shown in the map. Ask a volunteer to locate the compass rose, a symbol that indicates the directions north, south, east, and west. Next, ask the students to translate pictorial symbols on the map by using its key, which is usually found in a small box in the map's corner. Finally, explain how scale can be shown on a line that is divided into sections, each of which represents a larger unit of measure. Tell students, for example, that a one-inch section on the map can stand for a mile in actual distance. Have the children take turns in class using the sample maps to find examples of each feature. They should also discuss their usefulness.
For homework, ask each student to bring in a map from home, being sure to ask a parent or caregiver for permission first. As part of the assignment, tell the children to be ready to locate and discuss the title, compass rose, map key, and scale on the maps they find.
Measurement Units and Scale
At the conclusion of map sharing, focus the discussion on scale and its purpose. Explain how scale keeps size and distance in their proper proportion while allowing us to "carry the world" in the glove box of a car.
Now really ignite enthusiasm for mapmaking. Tell students that a "hidden treasure" will soon be placed somewhere in the classroom. To track it down, they will need a classroom map that is very accurate and drawn to scale. The treasure, of course, is the incentive to spark a review of the various units of both metric and standard linear measure: miles, kilometers, yards, meters, feet, inches, and centimeters. Have students form groups of three or four to discuss which units and scale would be best to use. Most classes eventually decide on scales such as 1 inch = 1 yard or 1 centimeter = 1 foot.
Make the Maps
Remind students that a good map has a title, a key with clear symbols, a compass rose showing direction, and a guide to scale. Provide graph paper (divided into one-inch- or one-centimeter-square boxes, depending on the scale selected) on which their maps can be drawn. Make available measuring tools such as rulers, yardsticks, meter sticks, measuring tapes, and string.
Children can work together to do the actual measurement of the room but should keep their own notes and design their own individual maps. Guide students to measure only things that don't move by themselves, such as desks, and remind them that placement and size of furniture are important. Plan on at least two 40-minute classes to complete the measurement and mapmaking.
The Dot Marks the Spot
Collect the completed maps. Then ask for a volunteer who will go out into the hall while you place a small adhesive dot or marker somewhere in the room. On that child's treasure map, mark the corresponding spot with an X. Place the dot in a location where it cannot easily be spotted (such as inside a desk or under a chair)-insurance that the treasure-hunter will not immediately see the marker and so must rely on the map to locate it. Call the student into the room, hand back the marked map, and send him or her off to find the hidden dot. Once the child succeeds, produce a "treasure chest" and have him or her choose a prize such as stickers or pencils. (Ones printed with "I Love Math" are particularly nice and can be found in the catalog published by the National Council of Teachers of Mathematics. See Math & Map Resources.)
Have each student take a turn using his or her map to find treasure, while classmates cheer each youngster on! Even though they won't find any doubloons, students will be delighted to find that math can be rewarding!