Observe the ruler, it is marked in centimeters.

The long marks are centimeters, and the shorter marks are millimeters and there are 10 millimeters (mm) for each centimeter (cm).

The object starts at 0^th short mark and ends at 35^th short mark. \

Length of object = 35 millimetres.

= 30 mm + 5 mm                   (Rewrite 35 as 30 + 5)

= 3cm + 0.5 cm                      (10 millimetres = 1 centimetre)

= 3.5 cm                                  (Add: 3 + 0.5 =3.5)

The length of the object is 3.5 cm.