*physics *
without using your spring scale, estimate the order of magnitude of the mass of your calculator in grams from what you judge to be its size, using the fact that the density of water is 1 g/cm3. assume that the density of water is about the same as the density of your calculator.
1 g
102 g
104 g
106 g

My calculator is about 1cm thick, 7cm wide, and 13cm long.

Its volume is (length) (width) (thick) = (13 x 7 x 1) = 91 cm³ .

The question wants me to assume that the density of my calculator
is about  the same as the density of water.  That doesn't seem right
to me.  I could check it easily.  All I have to do is put my calculator
into water, watch to see if sinks or floats, and how enthusiastically. 
I won't do that.  I'll accept the assumption.

If its density is actually 1 g/cm³, then its mass is about 91 grams.

The choices of answers confused me at first, until I realized that
the choices are actually 1g, 10² g, 10⁴ g, and 10⁶ g.

My result of 91 grams is about 100 grams ... about 10² grams.

Your results could be different.