Tính 250 mm + 100 mm 420 mm – 150 mm 25 mm + 3 mm 64 mm – 15 mm

250 mm + 100 mm = 350 mm

25 mm + 3 mm = 28 mm

11 mm x 3 = 33 mm

420 mm – 150 mm = 270 mm

64 mm – 15 mm = 49 mm

50 mm : 2 = 25 mm