 
 <prompt> Eric na-agụ 20 marbul. O nwere 12 marbul ocha, 6 marbul blu, ma ọ bụrụ na ọ nwere marbul ndụmọdụ. Kama marbul ndụmọdụ ka Eric nwere? <response>: ```Eric na-akpọ 12 + 6 = 18 marble ncha na afor.
N'ihi na ya enweghị 20 - 18 = 2 marble akwụkwọ.

Nke a bụ ihe ọ bụla: 2.``` 