To calculate the mass of the wooden block, you can use the formula:
Mass (in grams) = Density (in g/cm³) * Volume (in cm³)
In this case, the density of the wooden block is 3 g/cm³, and its volume is 1240 cm³.
Mass = 3 g/cm³ * 1240 cm³ = 3720 grams
So, the mass of the wooden block is 3720 grams.