the number of significant figures in the measured length is 4. the calculated area and the volume should therefore be rounded off to 4 significant figures.
surface area of the cube `=6 (7.203)^(2) m^(2)`
`=311.299254 m^(2)`
`=311.3 m^(2)`
Volume of the cube `= (7.203)^(3) m^(3)`
`=373.714754 m^(3)`
`=373.7 m^(3)`