а) 458+333+42+67 = (458 + 42) + (333 + 67) = 500 + 400 = 900
б) 635+308+1365+392 = (635 + 1365) + (308 + 392) = 2000 + 700 = 2700
а) 458+333+42+67 = (458 + 42) + (333 + 67) = 500 + 400 = 900
б) 635+308+1365+392 = (635 + 1365) + (308 + 392) = 2000 + 700 = 2700