standard_description: Use parentheses, brackets, or braces in numerical expressions, and evaluate expressions with these symbols.
problem_activity: Problem 1
Solve. Show or explain your work.
$${2{5\over8}+4{2\over3}}$$
Problem 2
Sang needs
$$3\tfrac{1}{2}$$
feet of string to make a necklace and
$$2\tfrac{1}{4}$$
feet of string left. How much string, in feet, did Sang have before making the necklace?


aligns: no