So I needed to adjust a value (the odds of a horse winning a race) that has a fractional part and an integer part (i.e. a ‘double’, or ‘float’). The standard numeric input on an iPhone doesn’t include a decimal point, so I needed to trigger a different input device.
I ended up with this:
<input type="number" pattern="[\d\.]*" step="0.01" inputmode="numeric">