This paper considers the Cauchy problem for the nonālinear dynamic string equationĀ of Kirchhoffātype with timeāvarying coefficients. The objective of this work is to develop a timeādomain discretization algorithm capable of approximating a solution to this initialāboundary value problem. To this end, a symmetric threeālayer semiādiscrete scheme is employed with respect to the temporal variable, wherein the value of a nonālinear term is evaluated at the middle node point. This approach enables the numerical solutions per temporal step to be obtained by inverting the linear operators, yielding a system of secondāorder linear ordinary differential equations. Local convergence of the proposed scheme is established, and it achieves quadratic convergence regarding the step size of the discretization of time on the local temporal interval. We have conducted several numerical experiments using the proposed algorithm for various test problems to validate its performance. It can be said that the obtained numerical results are in accordance with the theoreticalĀ findings.