Do numbers need to be encase in "quotes" when building a json object array?

It can be either. Both strings and numbers are valid JSON values. Choosing which one depends on how you are going to use it, although in the Part 2 video, it doesn't matter since JavaScript numbers are coerced into strings automatically. For example:

var stringVal = "23";
var numVal = 23;
console.log("Points: " + stringVal);
console.log("Points: " + numVal);

Both console.log statement will function as expected since numVal is automatically converted to a string. Personally, I would represent numbers are Numbers since it more accurately describes the data as a number rather than as a "numeric string" and allows for sensible operations. For example:

var stringVal = "23";
var numVal = 23;
console.log("Points: " + (stringVal + 1));
console.log("Points: " + (numVal + 1));

The first console.log will return "Points: 231" while the second is most likely what you want (24). To remedy the first case, you'd have to do something like:

console.log("Points: " + (parseInt(stringVal, 10) + 1));

Which is arguably more convoluted.