Callie H. answered 04/14/19
National Board Certified Teacher can help you/your child in all areas
I presume the final question is: How many flats should she buy?
First you need to figure out how many plants she needs. If the bed is 63 feet long, and she is putting a plant every foot, she will need 64 plants (presuming she starts at the edge, or 0).
If each flat contains 6 plants, we divide 64 by 6 to see how many flats she needs. 64/6 = 10 4/6.
If she's not allowed to break up a flat, she'll need 11 flats. If she is allowed to break up a flat, she'll need 10 4/6, which reduces to 10 2/3 flats.