  Math word problem (MWP) solving aims to understand the descriptive math
problem and calculate the result, for which previous efforts are mostly devoted
to upgrade different technical modules. This paper brings a different
perspective of \textit{reexamination process} during training by introducing a
pseudo-dual task to enhance the MWP solving. We propose a pseudo-dual (PseDual)
learning scheme to model such process, which is model-agnostic thus can be
adapted to any existing MWP solvers. The pseudo-dual task is specifically
defined as filling the numbers in the expression back into the original word
problem with numbers masked. To facilitate the effective joint learning of the
two tasks, we further design a scheduled fusion strategy for the number
infilling task, which smoothly switches the input from the ground-truth math
expressions to the predicted ones. Our pseudo-dual learning scheme has been
tested and proven effective when being equipped in several representative MWP
solvers through empirical studies. \textit{The codes and trained models are
available at:} \url{https://github.com/steven640pixel/PsedualMWP}.
\end{abstract}
