Student rolls all the dice, randomly picks three of them, and creates three-digit number (see 938 in the left picture). Then looks for a dice with value equalling absolute value of the difference between the first and second dice of the triplet (|9-3|=6) and does the same thing with the second and third dice (|3-8|=5) and places both dice below the triplet. By following this principle the student places one last dice below the second row and creates so called difference cluster.

This activity is a great way to teach the concept of absolute value, when only the raw difference is important. There is actually no need of mentioning the term absolute value, we ask only by how much the numbers differ. In this way children also easily learns to deal with number zero.

The top row may be formed also from four dice. The exercise then gets much harder and requires several combinations and rearrangements of the dice to find the valid solution. Yet from experience children prefer this over the former three-dice setting. Keep in mind that in this case children must use all ten dice and it might not always have a valid solution (probably, we have never saw such a case).