standard_description: Understand that attributes belonging to a category of two-dimensional figures also belong to all subcategories of that category. For example, all rectangles have four right angles and squares are rectangles, so all squares have four right angles.
problem_activity: Problem 1
Find the value of each of the following.
a.
$${{1\over4}}$$
of
$${{12}}$$
b.
$${{3\over4}}$$
of
$${{12}}$$
Problem 2
There are 21 students in the chess club.
$$2\over3$$
of them are girls. How many girls are in the chess club?


aligns: no