standard_description: Explain why a fraction a/b is equivalent to a fraction (n × a)/(n × b) by using visual fraction models, with attention to how the number and size of the parts differ even though the two fractions themselves are the same size. Use this principle to recognize and generate equivalent fractions.
Grade 4 expectations in this domain are limited to fractions with denominators 2, 3, 4, 5, 6, 8, 10, 12, and 100.
problem_activity: Problem 1
The images below are maps with different scales. What do you notice? What do you wonder?
[IMG]
[IMG]
Problem 2
The map below shows Boston Common and Boston Public Garden. Perla walked around the outside perimeter of the Common and the Public Garden. About how far did she walk?
[IMG]
Problem 3
On the map below,
$${{1\over4}}$$
inch represents one mile. Candler, Canton, and Oteen are three cities on the map.
[IMG]
a.   If the distance between the real towns of Candler and Canton is 9 miles, how far apart are Candler and Canton on the map?
b.   If Candler and Oteen are
$${3 {1\over2}}$$
inches apart on the map, what is the actual distance between Candler and Oteen in miles?


aligns: no