Final answer:
After dividing 106 seashells into 6 piles evenly, Alex will have 4 seashells leftover, which she will use for a craft.
Step-by-step explanation:
The question asks how many seashells Alex will use for a craft after she sorts her collection of 106 shells into 6 piles. We need to calculate the number of shells that will not fit evenly into the piles. To do this, we perform a division where 106 is divided by 6. The quotient represents the number of complete piles, while the remainder will be the number of shells left over for the craft.
We calculate 106 ÷ 6 = 17 with a remainder of 4. So, Alex will have 4 seashells to use for her craft.