One good trick is to have in your imagination some examples of differently
numbered things.
For example, can you think of something familiar that has
100 things? 1000 things? 10,000 things?
Rather than continuing to add zeros here, we might use "scientific notation",
which just displays the "number of zeros" in a quantity.
This is especially
useful for huge numbers, like the number of atoms in a grain of sand.
This
could be written
80 000 000 000 000 000 000,
but is perhaps more readable
as
8x10^19,
that is, 8 with 19 zeros after it.
These zeros represent
"orders of magnitude".
What about units?
What are good units for measuring things in?
Some things formally make sense as whole numbers (or `real' numbers).
Some are measured in funny units (grams, megatons, Sieverts, dollars,...)