How to build a Calculator using Javascript such as below ?

After completing the setup of your html css and js project you will now have to insert some front end code to build your calculator. Below is a html code that you have to copy and paste in your index.html file. 

              <button>7</button>
              <button>8</button>
              <button>9</button>
              <button>+</button>
              <button>4</button>
              <button>5</button>
              <button>6</button>
              <button>-</button>
              <button>1</button>
              <button>2</button>
              <button>3</button>
              <button>*</button>
              <button>0</button>
              <button>C</button>
              <button>=</button>
              <button>/</button>