Malia bought a block of wax to make candles. She used 3.5 pounds of the wax to make vanilla-scented candles and has less than 5 pounds of wax left to make orange-scented candles.

To make orange-scented candles, Malia has less than 5 - 3.5 = <<5-3.5=1.5>>1.5 pounds of wax left. Answer: \boxed{1.5}.

To find out how much wax Malia has left to make orange-scented candles, we need to subtract the amount of wax used to make the vanilla-scented candles from the total weight of the wax she initially bought.

Step 1: Subtract the weight of the wax used to make the vanilla-scented candles from the total weight of the wax Malia bought.
Total wax - Wax used for vanilla-scented candles = Wax left for orange-scented candles

Step 2: Calculate the wax left for orange-scented candles.
Wax left for orange-scented candles = Total wax - Wax used for vanilla-scented candles

Let's use the given information to calculate the amount of wax Malia has left to make orange-scented candles.

To find out how much wax Malia has left to make orange-scented candles, we need to subtract the amount of wax used to make vanilla-scented candles from the total amount of wax she initially had.

Let's assume Malia initially had a certain number of pounds of wax, which we'll call "x".

Malia used 3.5 pounds of wax to make vanilla-scented candles. This means that after making those candles, she has "x - 3.5" pounds of wax left.

We also know that she has less than 5 pounds of wax left for making the orange-scented candles. So we can set up the following inequality:

x - 3.5 < 5

To find the value of x, we can add 3.5 to both sides of the inequality:

x - 3.5 + 3.5 < 5 + 3.5

This simplifies to:

x < 8.5

So, Malia initially had less than 8.5 pounds of wax before making any candles. Now, if you know the exact amount of wax she initially had, you can substitute it into the equation to determine the remaining amount.