Chapter 2, Problem 2.73P

Two $\text{p}{K}_{\text{a}}$ values are reported for malonic acid, a compound with two $\text{COOH}$ groups.

Explain why one $\text{p}{K}_{\text{a}}$ is lower and one $\text{p}{K}_{\text{a}}$ is higher than the $\text{p}{K}_{\text{a}}$ of acetic acid ${\text{(CH}}_{\text{3}}\text{COOH},\text{p}{K}_{\text{a}}=4.8)$