Start from what you can observe, then connect it to the model scientists use.
Look for one measurable consequence: a colour change, a temperature change, a spectrum, a pressure, a mass or a time.
A model is useful because it explains and predicts. It is not a literal photograph of nature.
Start by identifying the quantity, element or phenomenon being studied, then connect it with a concrete situation. A scientific formula becomes much easier to understand once every term and unit has a clear physical meaning.
Mendeleev’s habit: always check the order of magnitude. A calculation can look correct while giving a physically impossible result when a unit has been forgotten or converted incorrectly.