“When will we ever use this?” is a question that all Math teachers often hear. Our Grade 7 Pre-Algebra students have been learning about ratios, proportions, and similar figures. They put their knowledge into practice by using “indirect measurement” to find the height of a fir tree and a back-stop support.
Students placed a mirror between themselves and the object being measured. They then measured the distance from themselves to the mirror, from the mirror to the base of the object, and their own height. Then, using these measurements in a proportion, they calculated the height of the object. We discussed the acceptability and closeness of their calculations.
It was a great morning to be outside doing some Math.