What happens if you multiply something? It gets bigger, or you get more of them. A multiple
, then is bigger than the original number.
is the "opposite". It's what you get when you "take a number apart".
I teach older kids, so I'm not familiar with a lot of the manipulatives available, but I'm sure you have blocks or something like that where you could "take apart" a number, or build several of the same number and add them up. That would be my thought for kids that age. I hope this helps some