Spell "bag"
B-A-G
Write this word on the board
bag
Spell "computer"
C-O-M-P-U-T-E-R
Spell "pencil case"
P-E-N-C-I-L-C-A-S-E
What's that? - It's a bag.
What's this? - It's a computer.
What's this? - It's a pencil case.
Write this word on the board
rubber
Write this word on the board
pencil case
Spell "rubber"
R-U-B-B-E-R
Write this word on the board
computer
What's that? - It's a rubber.