Line references

Just as with a variable, if you go back and modify the value of the variable, every expression in which the variable appears will automatically update with the new value.
A similar effect is achieved with line references but without using variables.
Simply reference a line, and the result of that line will be inserted at the cursor's position.
From that point on, any modification to the referenced line will be reflected in the lines that contain it.

You can reference a line using the already familiar ALT ↑ or ALT ↓ buttons, with the difference being that if the selected line does not contain a variable declaration, then the line itself will be referenced.

$16/day
{1} * 7days
{1} * 365days

The background of the inserted line references is blue, and they contain the result of the referenced line.
Similarly to variables, line references are also marked with colors to help indicate where they are used, or which line they refer to.

In the note above, both the second and third lines contain a reference to the first line. Try modifying the first line and observe how the second and third lines change accordingly.

Additionally, try referencing lines yourself using the ALT ↑↓ buttons, as you have already learned with variables.

Similarly to jumping to variables, by pressing CTRL B while standing on a reference, you can jump to the referenced line.