I made this to replace the speaking activity for Lesson 2B (How many CDs do you have? - I have Twenty CDs) in the 5th Grade Junior Total English textbook, but hopefully it can be useful for other occasions too.
This game can be done in pairs, so you'll need 1 sheet per 2 kids in the class. I printed mine on A3 paper and laminated them so that they can be reused. I've uploaded the pdf to print as-is as well as the ppt file if you want to edit it.
How to play:
1. One half of the pair secretly chooses one of the characters on the sheet.
2. The other half of the pair asks them the target question: How many pencils do you have? How many Rulers do you have? etc. until they figure out who their partner is.
3. Switch roles and repeat as many times as you give them time for.
Since this is a speaking activity, I chose not to include any example sentences on the worksheet, but if you feel that they're necessary, you can write them on the board.
The phrases necessary to do this activity are:
"How many (pencils) do you have?"
"I have 5 pencil(s)."
"You are (Chika)!"
"That's right!/Try again."
(For 0, I recommend using "I have zero pencils." over "I don't have any pencils." at the 5th grade level.)