The Escalator Boxcar Train (EBT) method is a well known and widely used numerical method for onedimensional structured population models of McKendrick-von Foerster type. Recently the method, in its full generality, has been applied to aged-structured two-sex population model (Fredrickson-Hoppensteadt model), which consists of three coupled hyperbolic partial differential equations with nonlocal boundary conditions. We derive the simplified EBT method and prove its convergence to the solution of Fredrickson-Hoppensteadt model. The convergence can be proven, however only if we analyse the whole problem in the space of nonnegative Radon measures equipped with bounded Lipschitz distance (flat metric). Numerical simulations are presented to illustrate the results.Functions c m , c f and c c describe the rates of disappearance of individuals, where disappearance of males or females is related to death, while couples disappearance reflects divorce or death of one of spouses. Functions b m and b f are birth rates of males and females. Observe that the mentioned coefficients depend on ecological pressure in a nonlinear manner, that is they are nonlocal operators depending on the distribution of males, females and couples.The marriage function T models the number of new marriages of males and females of age x and y, respectively, at time t. It also depends nonlinearly on the distribution of individuals. The choice of this function is a subject of ongoing discussions, see [14,15,21,23], due to the properties like heterosexuality, homogeneity, consistency or competition. In this paper we follow the formulation proposed in [18], namelyx, y)dy is the amount of unmarried males and u f (t, y) − ∞ 0 u c (t, x, y)dx is the number of unmarried females. The functions h, g ∈ L 1 (R + ) ∩ L ∞ (R + ) describes the distribution of eligible males/females on the marriage market. We further assume that youngsters do not marry below a certain age a, i.e. h(x) = g(y) = 0 for x, y ∈ [0, a 0 ) .( 1.3)The regularity of the remaining coefficients and their nonlinear dependences are presented in detail in Section 3.2. The aim of the paper is analysis and convergence of a simplified EBT scheme, see Subsection 2.1, corresponding to (1.1). More precisely, we show convergence of the numerical integrator embedding the underlying problem (1.1) and its numerical scheme in a space of measures. The nonlinear age-structured, two-sex population model was presented and analysed in a space of nonnegative Radon measures in [25], where the well possedness of the problem was proved.Recently, the EBT method has been derived in [10] for a partially linearised system of aged-structured equationsLemma 3.3. Let µ = J i=1 m i δ xi andμ = J i=1m i δx i , where J ∈ N, x i ,x i ∈ R N + and m i ,m i ∈ R + . Then, d N (µ,μ) ≤ J i=1 ( x i −x i m i + |m i −m i |) . γ + J v=Bn h(x c vj (t)) m m v (t) − J w=Bnm c vw (t) + J w=Bn g(y c iw (t)) m f w (t) − J v=Bnm c vw (t).