What is big? What is small? A sense of scale allows students to make comparisons with common measurements. Although a sense of scale requires more memorization than conceptual understanding, it is a powerful building block for quantitative literacy.

Students possess physical sense for common measurements such as:

• Length of a meter
• Weight of a kilogram

Students have memorized common measurements specific to the topic at hand such as:

• Population of the U.S.
• Population of the world
• Population of the city, region, or state in which they live
• Distance between important cities or other geographic locations
• Average wage or income
• Poverty rate
• Number of casualties in World War I
  
• Height of an average person
• Weight of an average person

Students are aware of, and try to avoid, the anchoring effect.

Questions

What specific numbers should students have at their fingertips within a given field of study or topic?  What numbers provide a shorthand to help students make comparisons, evaluate change, or comprehend distance?