If a number is enclosed in quotes, it's a ______.

What kind of operation can be done on a number variable that, in one particular case, can't be done on a string variable? Answer with a 4-letter word. (It would be a five-letter word in British usage.)

What is the value of orderTotal?
var merchTotal = 100;
var shippingCharge = 10;
var orderTotal = merchTotal + shippingCharge;

Drag-and-drop. Holding down the left mouse button, drag the pieces of code onto the screen to form a statement that declares a variable and assigns a value to it.

Click in the box and type the next character. I'll autocomplete. Don't type spaces.

In a single statement, declare the variable numberAsString and assign the number 3 to it as a string.

Fail-safe coding. If you type the wrong character, I'll cancel the keystroke. Type spaces.

Assign to the variable caseQty, which has already been declared, the value 144.

In a single statement declare a variable and assign a number to it. (You've learned only two rules for naming variables so far—no quotes and no initial number—so they're the only ones I'll hold you to.)

In a single statement declare a variable and assign to it the sum of 2 other variables. (You've learned only two rules for naming variables so far, so they're the only ones I'll hold you to.)

Rewrite this statement so the variable can be used in a math operation.
var num = "9";

Assign the sum of 2 numbers to a variable, which hasn't been declared beforehand. (You've learned only two rules for naming variables so far, so they're the only ones I'll hold you to.)

In one statement declare a variable. In a second statement assign it the sum of 2 numbers. (You've learned only two rules for naming variables so far, so they're the only ones I'll hold you to.)

Time goal: 20 seconds. (The timer starts when you click in the answer field.) In a single statement declare a variable and assign a number to it. You've learned only two rules for naming variables so far—no quotes and no initial number—so they're the only ones I'll hold you to. (The timer starts when you click in the answer field.)

Time goal: 25 seconds. In a single statement declare a variable and assign to it the sum of 2 other variables. (You've learned only two rules for naming variables so far, so they're the only ones I'll hold you to.)

Time goal: 20 seconds. Rewrite this statement so the variable can be used in a math operation.
var num = "9";

Time goal: 30 seconds. Assign the sum of 2 numbers to a variable, which hasn't been declared beforehand. (You've learned only two rules for naming variables so far, so they're the only ones I'll hold you to.)

Time goal: 30 seconds. In one statement declare a variable. In a second statement assign it the sum of 2 numbers. (You've learned only two rules for naming variables so far, so they're the only ones I'll hold you to.)

Time goal: 35 seconds. In the first statement declare a variable and assign it a number. In the second statement, change the value of the variable by adding it together with a number.

Live coding exercise: Declare a variable and assign it a number. Then code an alert, specifying the variable, not the number, as the message. Click the Run It button to run your code live. Type out the code. If you copy and paste it from the screen showing the correct code, it may not work.

Live coding exercise:

1. Declare a variable and assign it a number.
2. Double the variable's value by adding the variable to itself.
3. Display the variable's value in an alert, specifying the variable, not the number, as the message.

Type out the code. If you copy and paste it from the screen showing the correct code, it may not work.