A student is learning about positive and negative numbers with manipulatives. Each black cube represents + 1 , and each white cube represents − 1 . If there are currently 15 black cubes on the student's desk, how many white cubes must the student add to the desk for the combined value of the cubes to represent 0 ?

15 white cubes

Step-by-step explanation:

Given

Required

Determine the number of white cubes needed to represent 0

To solve this question, we make use of the following equation.

If there are 15 black cubes, the the 15 black cubes is worth: +1 * 15

Substitute +1 * 15 for the Black Cubes

Collect Like Terms

Recall that 1 white cube is worth -1

So, the number of white cubes is:

Hence, the student needs 15 white cubes

15

step-by-step explanation: