Hey there!
To find the area of the rectangular play area, all you need to do is multiply your given length and width of the play area together.
7.5 m × 5.3 m = 39.75 m²
Since this measurement is accounting for a two-dimensional space instead of a one-dimensional line, the unit of measurement used will be m² instead of just m.
Your answer will be 39.75 m²-worth of foam.
Hope this helped you out! :-)