so basically sam split the 1000 to 2 groups so we have 1000 ÷ 2
now the first group divided the 500 (since 1000÷ 2 is 500) among five children so it would be 500 ÷ 5 which equals 100 per child and the second group divided their 500 between to boys, so you would get 500÷2 which is 250
so for group one it would be: 1000÷2÷5 which equals 100 per child and the second group is 1000÷2÷2 which equals 250 for each brother