title: how to increase float without strange number
body: <p>so i tried to increase number with float, but sometime it comes strange number but i just want a number like <code>0.1, 0.2, until 5.0</code> but it sometime comes with strange number like <code>0.9000001</code></p>
  
  <p>this is my code to increase the float</p>
  
  <pre><code>addRattingBtn.onClick {
          quantity += 0.1f
          if (quantity &gt;= 5.0f) {
              toast("maximum")
              return@onClick
          }
          totalRatting(quantity.toBigDecimal())
      }
  </code></pre>
  
  <p>i already convert it to BigDecimal but it still not work.
  why this is happen? and how to make it right. please help</p>