5tth grade math
posted by tryston .
every student in a second grade class sends a valentine to each of the other students in the class, for a total of 306 valentines.How many students are in the class.

The square root of 306 is about 17.5.
So I multiplied 17 * 17 and got 289 Valentines.
There must be 18 students in the class  and the each sent 17 cards. 
i need help on extended response

18 Students is the answer you exclude the student passing out the Valentines. So 18 students received 17 valentines...