How do I find the flats,longs, and units.

3 flats, 1 long, and 5 units with one dimension of 21. i) To set up the division, these pieces need to be traded for flat(s), long(s), and unit(s). To complete the division, these pieces need to be vii) ii) iii) vi) iv) V) ii) flat(s), long(s), and unit(s) in region ii) iii) flat(s), long(s), and unit(s) in region iii) iv) flat(s), long(s), and unit(s) in region iv) V) flat(s), long(s), and unit(s) in region v) with dimensions vi) for edge vi) vii) for edge vii) viii) Multiplication fact: 21 x