Hello, I have a DE10-Lite board that I am trying to convert BCD to Decimal. Hear is my code and I am having issues getting is to work, can you see where I'm going wrong?

//////////////////// BCD TO DECIMAL //////////////////////////////

module DE10_LITE_Default( input [1:0]KEY,

input [9:0]SW,input CLK,

output [9:0]LED,

output [7:0]HEX_0,output [7:0]HEX_1, output [6:0]HEX_2, output [6:0]HEX_3); // HEXOUT_0

reg [3:0]module_select;

wire [7:0]add_out;

wire [9:0]math_carry;

Arithmetic math_block(SW[9:8],SW[7:0],math_carry[9],add_out[7:0]);

wire [9:0]logical_out;

Logical logic_block(SW[9:8],SW[7:0],logical_out[7:0]);

wire [3:0]compare_out;

Comparison compare_block(SW[9:8],SW[7:0],compare_out[3:0]);

wire [9:0]soultion_output;

solution(CLK, soultion_output[9:0]);

//display what the sub-module selection is on HEX_2

SevenSegment HEX2({1'b0,1'b0,SW[9],SW[8]},HEX_2[6:0]); // HEXOUT_2

//display what module number the user is in on HEX_3

SevenSegment HEX3(module_select[3:0],HEX_3[6:0]); // HEXOUT_3

//Use the first button to cycle one way through the different modules

always@(posedge KEY[0],posedge KEY[1])

begin

module_select = (module_select + 1) % 4;

end

//use multiplexors to switch between the different outputs on the first two HEX displays depending on the module selection

wire [3:0]HEX0_in;

MUX HEX0_MUX({4'b0000,compare_out[3:0],logical_out[3:0],add_out[3:0]},module_select[1:0],HEX0_in[3:0]);

defparam HEX0_MUX.n = 4;

SevenSegment HEX0(HEX0_in[3:0],HEX_0[6:0]); // HEXOUT_0

wire [3:0]HEX1_in;

MUX HEX1_MUX({4'b0000,4'b0000,logical_out[7:4],add_out[7:4]},module_select[1:0],HEX1_in[3:0]);

defparam HEX1_MUX.n = 4;

SevenSegment HEX1(HEX1_in[3:0],HEX_1[6:0]); // HEXOUT_1

//if the processor is in arithmetic mode, have the most significant decimal point match the multiplication carry,

//and least significant match the division carry

assign HEX_0[7] = ~(~module_select[0] & ~module_select[1] & SW[9] & SW[8] & math_carry[9]);

assign HEX_1[7] = ~(~module_select[0] & ~module_select[1] & SW[9] & ~SW[8] & math_carry[9]);

//use a 10 bit multiplexor to switch between the different outputs of the LEDs depending on the module selection

MUX LED_MUX({solution_output[9:0],10'b0000000000,logical_out[9:0],math_carry[9:0]},module_select[1:0],LED[9:0]);

defparam LED_MUX.n = 10;

endmodule