Where can F# actually save time and money?

[<Measure>] type kg //define a unit of measure
let myMass = 80.0<kg> //define a mass in kg

[<Measure>] type m //define a unit of measure
[<Measure>] type s //define a unit of measure
let g = 9.8<m/s^2>  //define gravitational acceleration (with units)
let myWeight = myMass * g // result is 784.0<kg m/s ^ 2>

//ERROR: The unit of measure 'm' does not match the unit of measure 'kg m/s ^ 2'
let stupidError = myWeight + myMass