Math with numbers
Numbers are the most common kind of value. You can combine them with the usual math operators and store the result in a variable:
+add,-subtract*multiply,/divide%remainder — what's left after dividing (e.g.7 % 3is1)
Reassigning
A variable declared with let can be reassigned — just use = again, without let. The box keeps its name but holds a new value:
let score = 5;
score = score + 3; // score is now 8NOTE
score = score + 3 looks odd, but the right side is computed first (5 + 3), then the answer is stored back into score.