\textbf{Daniel is learning conservation of number, a skill that Piaget believed children learn in the concrete operational stage} 
\textbf{Daniel is learning that five pennies spread out on his desk are the same number of coins as five pennies in a pile. According to Piaget, how old is Daniel likely to be?} 
Options:
1. 1~\textbf{year} 
2. 2~\textbf{years} 
3. \textbf{4 years} 
4. \textbf{8 years} 
5. \textbf{13 years} 