Slider
Slider. Drag the thumb; the arrows step it in gears — Shift coarse, Alt fine, held arrows accelerate. readout shows the value. Space on the focused thumb sweeps it; play adds the button.
source
<notatio-tangle>
<notatio-slider name="k" value="2" min="0" max="10" step="0.5" readout play />
so
<notatio-dynamic value="_k^2" />
is its square.
</notatio-tangle>