Вправи 501 - 600 » 559

890 – 7 • 9 + 1 = 890 – 63 + 1 = 820 + 1 + 70 – 63 = 821 + 7 = 828 470 – 350 + 189 = 120 + 189 = 120 + 180 + 9 = 300 + 9 = 309 857 + 13 • 3 = 857 + (10 • 3 + 3 • 3) = 857 + (30 + 9) = 857 + 39 = 857 + 33 + 6 = 890 + 6 = 896 1000 – (259 + 711) = 1000 – (259 + 11 + 700) = 1000 – (270 + 700) = 1000 – 970 = 30