how I can show the sum of in a datagridview column?

Question

I need to show the sum of the count column from this datagridview, but I don\'t know how I can get to the data in the datagridview.

When I

Answer 1

 decimal Total = 0;

for (int i = 0; i < dataGridView1.Rows.Count; i++)
{
    Total+= Convert.ToDecimal(dataGridView1.Rows[i].Cells["ColumnName"].Value);
  }

labelName.Text = Total.ToString();