А) 164+428+436+272 = (164+436) + (428+272) = 600 + 700 = 1300
Б) 25 × 98 × 4 = 25 × 4 × 98 = 100 × 98 = 9800
В) 2 × 59 × 50 = 2 × 50 × 59 = 100 × 59 = 5900