Circle the number that is \textbf{closest to} $2.5$.  $3            2.1            2.494            2.449            2.51$ 
Overseas Competition->Knowledge Point->Calculation Modules->Decimals->Basic Understanding of Decimals->Comparing Decimals Overseas Competition->Knowledge Point->Calculation Modules->Decimals->Addition and Subtraction of Decimals->Subtraction of Decimals