In chemistry, a mole is a unit used for counting. A molecule is a single particle of a compound that has covalent bonding.
Let's consider water as an example.
One molecule of water is two hydrogen atoms bonded to an oxygen atom. H-O-H
Note: I ask my students to calculate molar masses to two places beyond the decimal because we work with centrigram balances for our labs. Some chem teachers will ask their students to calculate molar masses to only one decimal, others to three or more.