Question about mixing solutions?

I mixed CaCl2(aq) with H2C2O4(aq) and CaCl2(aq) with (NH4)2C2O4(aq) and my chem. teacher asked about precipitate and from the experiment precipitate formed in both solutions but much more with the second (aq) solution, so what can i conclude as to why, what is the difference between the to (aq) solutions is one stronger? please help me understand