A kids book, there were 3 or 4 kids being main characters and each had a wand that controls an element

Question

I don't remember much about it. But these 3 or 4 kids get a wand, and when they split the wand, each piece controlled an element. I also remember that an antagonist was a giant with 3 pairs of eyes, 3 sets of ears and 3 mouths. I think the giant wanted to make the wand whole and use its power.