a) 550 mm + 260 mm = 810 mm     180 mm × 4 = 720 mm

732 mm – 32 mm = 700 mm       720 mm : 8 = 90 mm

b) 327 ml + 400 ml = 727 ml       150 ml × 6 = 900 ml

1000 ml – 300 ml = 700ml        700 ml : 7 = 100 ml

c) 270g + 538g = 808g          240g × 3 = 720g

730g – 430g = 300g           960g : 6 = 16g