Word Problem

Sarah and Joey spent the entire afternoon playing in the snow.  When they came in they decided to have some hot chocolate to warm up.  Sarah added no marshmallows to her mug.  Joey dropped 3 marshmallows in his hot chocolate. 

Hint:  If it helps, draw the marshmallows in the space below.

Write the math equation: ______________________

How many marshmallows did Sarah and Joey use in all?  _______

Show your work!