5. Вычислите: 400 + 80 - 1 750 - 50 + 1 978 - 8 - 1 500 + 99 + 1 300 + 74 374 - 300

\[400 + 80 - 1 = 480 - 1 = 479\] \[750 - 50 + 1 = 700 + 1 = 701\] \[978 - 8 - 1 = 970 - 1 = 969\] \[500 + 99 + 1 = 500 + 100 = 600\] \[300 + 74 = 374\] \[374 - 300 = 74\]