Help please with this problem?

Question

beth has brought one and 3/7 lbs. of strawberries to her friend Lisa's house to make pies. how many more lbs. do they need if the recipe calls for five and 2/3 lbs.?

Answer 1

1(3/7) = 10/7, 5(2/3) = 17/3

17/3 - 10/7 = 119/21 - 30/21 = 89/21 = 4 and 5/21 lbs

They need 4 and 5/21 lbs more.