Сложите дроби полученную дробь сократите: а) 1 / 2 + 1 / 2 + 1 / 2 + 1 / 2 б) 1/3+2/3+1/3+5/3 в) 7/13+4/13+2/13 г) 1/96+5/96+11/96+31/96 д) 1/42+15/42+17/42+9/42 е) 19/78+53/78+37/78+21/78

Находим суммы дробных чисел с одинаковыми знаменателями:

а) 1/2 + 1/2 + 1/2 + 1/2 = 2/2 + 2/2 = 1 + 1 = 2;

Или:

1/2 + 1/2 + 1/2 + 1/2 = 4 х 1/2 = 4/2 = 2;

б) 1/3 + 2/3 + 1/3 + 5/3 = 3/3 + 6/3 = 1 + 2 = 3;

Или:

1/3 + 2/3 + 1/3 + 5/3 = 9/3 = 3;

в) 7/13 + 4/13 + 2/13 = 11/13 + 2/13 = 13/13 = 1;

г) 1/96 + 5/96 + 11/96 + 31/96 = 6/96 + 11/96 + 31/96 = 17/96 + 31/96 = 48/96 = 1/2 или 0,5;

д) 1/42 + 15/42 + 17/42 + 9/42 = 16/42 + 17/42 + 9/42 = 33/42 + 9/42 = 42/42 = 1;

е) 19/78 + 53/78 + 37/78 + 21/78 = 53/78 + 37/78 + 40/78 = 93/78 + 37/78 = 130/78 = 5/3 = 1 2/3.