How to get decimal values from text box and save it in SQL server

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C#

i have text box in win form
in which user give input
i am not sure in which formate user type value (either 10 or 10.0 or 10.00)
i am storing this value to sql server database
and want this value in (10.00 format either 10 or 10.0 or 10.00)
sql column data type is float

when i saw in table in sql i saw value as 10 or 10.0 or 10.00 which user type

but i want this value as 10.00 when user type 10 or 10.0

how can i manage this situation

can someone explain step by step ?

What I have tried:

using (SqlConnection conn = new SqlConnection(con))
{
using (SqlCommand cmd = new SqlCommand("usp_weightinsertdetails", conn))
{
cmd.CommandType = CommandType.StoredProcedure;

cmd.Parameters.AddWithValue("@Date", dateTimePicker1.Value);
cmd.Parameters.AddWithValue("@ProductName", textBox1.Text);
cmd.Parameters.AddWithValue("ProductPieces", int.Parse(textBox2.Text));

float weight, pc, avr;
weight = float.Parse(textBox3.Text.tostring("0.00"));
pc = float.Parse(textBox2.Text);
avr = weight / pc;

cmd.Parameters.AddWithValue("@ProductWeight", weight.tostring("0.00"));
cmd.Parameters.AddWithValue("@AveragePieceWeight", avr.tostring("0.00"));

conn.Open();
cmd.ExecuteNonQuery();