Answer:
subtraction= Mike is selling 50 apples. Kenny is selling 30 apples,"how many more" apples does mike have than ken?
50- 30 = 20
mike has 20 "more" apples than ken.
there are 15 kindergarteners, "but only" 10 chairs, "how many" chairs would the teachers have to "take away" from the room next door?
15- 10=5