standard_description: Solve word problems involving addition and subtraction of fractions referring to the same whole, including cases of unlike denominators, e.g., by using visual fraction models or equations to represent the problem. Use benchmark fractions and number sense of fractions to estimate mentally and assess the reasonableness of answers. For example, recognize an incorrect result 2/5 + 1/2 = 3/7, by observing that 3/7 < 1/2.
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