Elm runtime error SSCCE

import Html exposing (beginnerProgram, div, button, text)
import Html.Events exposing (onClick)


main =
  beginnerProgram { model = 5, view = view, update = update }


view model =
  div []
    [ button [ onClick Decrement ] [ text "-" ]
    , div [] [ text (toString ((5 % model) * 0 + model)) ]
    , button [ onClick Increment ] [ text "+" ]
    ]


type Msg = Increment | Decrement


update msg model =
  case msg of
    Increment ->
      ((5 % model) * 0 + model) + 1

    Decrement ->
      ((5 % model) * 0 + model) - 1