1-on-1 Warm-up Ideas?

Hi! I tutor a 2nd grade junior high school boy in a 1-on-1 (private) lessons once a week. He lived in the U.S. for 2 years when he was in elementary school so his listening & comprehension skills and speaking skills are excellent. His mother wants me to prep him for the Eiken Pre-1st grade test, so that's what we do for the main part of the lesson.

I like to start our lesson time with some short warm-up activities, but I'm running out of ideas! So far we have done Hangman using a variety of themes, Taboo!, Boggle, 20 Questions, and 2 Truths & a Lie.

Does anyone have any ideas for short, warm-up activities that require little / no prep? Thanks in advance!