Today’s #STEMsigns are proportionality, direct proportion, inverse proportion, rate, constant, quantity, and ratio!
*Signs shown on #STEMsigns are seen and used by the community and are not created by Atomic Hands. We encourage you to evaluate the sign and adopt or discard it; or develop a new sign!
[Video Description: Barbara, a white woman wearing a mottled gray tank top, is sitting in the foreground and the background has a window in the center and few plants on the left and right sides.
3:26 – A full screen image: This video is sponsored by RIT/NTID Regional STEM Center. Below is a logo of RIT on the left with National Technical Institute for the Deaf on the right.]
Transcript: Today’s #STEMsigns are: proportionality, direct proportion, inverse proportion, constant, quantity, rate, and ratio! What is proportionality? It describes a relationship between two quantities (amounts) that is always in the same ratio. What does it really mean? I will explain two types of proportionality to help understand the larger concept of proportionality. What is direct proportion? When one quantity increases, another quantity increases at the same rate. Or the other way around — When one quantity decreases, another quantity will also decreases at the same rate. You can read it mathematically as y = k*x where rate is the proportionality constant (k). For example, you know the age-old norm of the Deaf community… Deaf people tend to flock to the kitchen where light is the brightest. We can say mathematically that the number of Deaf people is directly proportional to brightness of light! The brighter the light is in a room, the more Deaf people will be present! We just discussed the first type of proportionality: direct proportion. The second type is inverse proportion. What is inverse proportion? When one quantity decreases at the same rate that the other increases. Or vice versa – when one quantity increases at the same rate as the other decreases. You can read it mathematically as y = k / x where rate is the proportionality constant (k). For example, you know the famous English phrase, “many hands make light work.” The more people working to accomplish a task, the quicker the task will be completed. We can say that the time it takes to complete the task is inversely proportional to the number of people working on it! When there are more people working, the task gets finished in a shorter amount of time!
