  In this paper, we consider some aspects of the numerical analysis of the
mathematical model of fractional Duffing with a derivative of variable
fractional order of the Riemann-Liouville type. Using numerical methods: an
explicit finite-difference scheme based on the Grunwald-Letnikov and
Adams-Bashford-Moulton approximations (predictor-corrector), the proposed
numerical model is found. These methods have been verified with a test case. It
is shown that the predictor-corrector method has a faster convergence than the
method according to the explicit finite-difference scheme. For these schemes,
using Runge's rule, estimates of the computational accuracy were made, which
tended to unity with an increase in the number of calculated grid nodes.
