const d = document.body.appendChild(

  document.createElement`div`)

d.innerHTML = `

<input 

  id="input"

  type="range" 

  min="-2" max="5" 

  value="0">

`

let val = 0;

console.log('drag slider...')

const range = (input.max - input.min);

input.oninput = () => {

  val = (input.value - input.min) / range

  console.log(input.value + ' - normalized = ' + val)

}