JavaScript Math.random()

The Math.random() method returns a random number from 0 (inclusive) up to but not including 1 (exclusive).

Math.random () : generates 0 to 1 random numbers

    <script>

            var a = Math.random();

            document.write(a);

    </script>

Math.random () *10 : generates 0 to 10 random numbers

        <script>

            var a = Math.random()*10;

            document.write(a);

    </script>

Math.random() used with Math.floor() can be used to return random integers

    <script>

            var a = Math.floor (Math.random() * 10) + 1;

            document.write(a);

    </script>