ГДЗ Математика 4 клас С.О. Скворцова, О.В. Онопрієнко (2021) - (1, 2 частина) |
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Розв'язок:
730 + 290 = 730 + (200 + 90) = (730 + 200) + 90 = 930 + 90 = 1020
730 + 290 = 730 + (70 + 220) = (730 + 70) + 220 = 800 + 220 = 1020
730 + 290 = (700 + 30) + 290 = (700 + 290) + 30 = 990 + 30 = 1020
730 + 290 = (720 + 10) + 290 = 720 + (10 + 290) = 720 + 300 = 1020
730 + 290 = (700 + 30) + (200 + 90) = (700 + 200) + (30 + 90) = 900 + 120 = 1020
730 + 290 = (730 + 300) – 10 = 1030 – 10 = 1020
730 + 290 = 73 дес. + 29 дес. = 102 дес. = 1020
710 – 380 = 710 – (300 + 80) = (710 – 300) – 80 = 410 – 80 = 330
710 – 380 = 710 – (310 + 70) = (710 – 310) – 70 = 400 – 70 = 330
710 – 380 = (700 + 10) – 380 = (700 – 380) + 10 = 320 + 10 = 330
710 – 380 = (30 + 680) – 380 = (680 – 380) + 30 = 300 + 30 = 330
710 – 380 = (600 + 110) – (300 + 80) = (600 – 300) + (110 – 80) = 300 + 30 = 330
710 – 380 = (710 – 400) + 20 = 310 + 20 = 330
710 – 380 = 71 дес. – 38 дес. = 33 дес. = 330