7. 980-80 - 100 290 + 70 140*6 480:6 640 - 40 + 200 680 + 50 260*3 360:9

980 - 80 - 100 = 800

290 + 70 = 360

140 * 6 = 840

480 : 6 = 80

640 - 40 + 200 = 800

680 + 50 = 730

260 * 3 = 780

360 : 9 = 40