Write an algebraic expression to model the unknown number situation. the sum of a number and one-third

A 1-column table with 5 rows. Column 1 is labeled Addition Words with entries add, increase by, more than, sum, total.

Which statements are true? Select all that apply.
You can replace "a number" with a variable to represent an unknown value.
You can replace "sum" with an addition sign.
You can replace "sum" with an multiplication sign.
You can replace "one-third" with One-third.
The correct algebraic expression is One-third n.