# 1.5 - Magnitude

The student, given a familiar problem situation involving magnitude, will

a)  select a reasonable order of magnitude from three given quantities: a one-digit numeral, a two-digit numeral, and a three-digit numeral (e.g., 5, 50, 500); and

b)  explain the reasonableness of the choice.

### BIG IDEAS

• So I can learn to estimate with reasonable numbers, for example, if I get a book from the library, does it have 1, 10 or 100 pages
• So that I can learn to understand that the weight of an elephant weighs 500 pounds, not 5 or 50
• So that I can learn that my school has 400 students not 4 or 40

### UNDERSTANDING THE STANDARD

• Magnitude refers to the size of a set.
• Exploring ways to estimate the number of objects in a set, based on appearance (e.g., clustering, grouping, comparing), enhances the development of number sense.
• To estimate means to determine a number that is close to the exact amount. When asking for an estimate, teachers might ask, “About how much?” or “About how many?” or “Is this about 10 or about 50?”
• Students should be provided opportunities to estimate a quantity, given a benchmark of 10 and/or 100 objects.

### ESSENTIALS

 The student will use problem solving, mathematical communication, mathematical reasoning, connections, and representations to Select a reasonable order of magnitude for a given set from three given quantities: a one-digit numeral, a two-digit numeral, and a three-digit numeral (e.g., 5, 50, or 500 jelly beans in jars) in a familiar problem situation. (a)Explain why a particular estimate was chosen as the most reasonable from three given quantities (a one‑digit numeral, a two‑digit numeral, and a three‑digit numeral), given a familiar problem situation. (b)

### KEY VOCABULARY

Updated: Aug 22, 2018