Final answer:
Joe would not write any ones in the expanded form of his 310 baseball cards.
Step-by-step explanation:
To determine how many ones Joe writes when writing the numbers of his 310 baseball cards in expanded form, we need to understand what expanded form means.
Expanded form is a way of writing a number as the sum of its place values.
For example, the number 310 would be written as (3 * 100) + (1 * 10) + (0 * 1) in expanded form.
Since there are no ones in 310, Joe would not write any ones when writing the numbers of his baseball cards in expanded form.
Therefore, Joe would not write any ones in the expanded form of his 310 baseball cards.