How to prevent auto rounding in arithmetic operations on python

Is there any way to prevent auto rounding in python while performing arithmetic operations? In the following code segment, n = 3; t is initially 0; x is initially 0; M is an arrray of 3 by 1 dimension; L = [[1 0 0] [2.56 1 0] [5.76 3.5 1]]; B = [[106.8] [177.2] [279.2]].

    def forwardSubs(M, n, t, L, B, x):    
        if(t == 0):
            y = (B[0][0])
            x = y
        else:
            y = (B[t][0] - (L[t][0])*x)
            for i in range(1, t):
                y = y - M[i][0]*L[t][i]     
        M[t][0] = y
        if(t+1==n):
            return
        forwardSubs(M, n, t+1, L, B, x)



The expected result is M = [[106.8]
                            [-96.208]
                            [0.76]]

But the program shows M = [[106]
                           [-96]
                           [0]]