Astudent is asked to convert measurements from meters to millimeters and from millimeters to meters. his answers are shown in bold in the choices shown below. on which choice did he make a mistake?
9070 mm = 90.7 m
652,222 mm= 652.222 m
37,500 mm = 37.5 m
1.02 x 106 mm = 1020 m

Option (a)

SI units or International System of Units is defined as basic set of measurement of seven units. The physical quantities and base units are as follows:

Therefore, SI units of physical quantities is known as base units and other units are known as derived units because they can derived from the SI units.

Length is measured in meter (m) as its base unit, the other derived units are km, cm, mm, etc. All these units are inter-convertible.

1 mm=0.001 m

Check for the correct conversion:

The conversion factor used will be

(a) Converting 9070 mm to m:

Thus, 9070 mm=9.07 m and the conversion done by student is incorrect.

(b) Converting 652,222 mm to m:

Thus, 652,222 mm=652.222 m and the conversion done by student is correct.

(c) Converting 37,500 mm to m:

Thus, 37500 mm=37.5 m and the conversion done by student is correct.

(d) Converting mm to m:

Thus,   and the conversion done by student is correct.

Therefore, the choice in which there is mistake is option (a)