Using place value to exchange equal amounts when renaming a number is called : Regroup
Simple example for a group is when you try to add up :
86 + 25
86 has 8 group of tens and 6 groups of one
25 has 2 groups of tens and 5 groups of one
after adding that up , now the number has 11 group of tens and 1 group of one, the result of that equation would be : 110
