Would it be confusing for the students or was it necessary to bring this up? Could the difference between ‘5 − 4 =’ ‘and 4 − 5 =’ be a critical aspect (i.e., the law of commutativity is not valid for subtraction)? “You could start with 4 − 5 = and discuss what happens in that case With ‘5 − 4 =’ it will be one left, but with ‘4 − 5 =’ it will be one missing. That difference is understood by every little child,” the researcher said. “Yes, and still we ignored that since we felt that we could not explain that,” T1 replied.