John has 135 baseball cards he gives his friend 64 how many does he have left? It does have a solution the answer is 71
Tell him to avoid this very common error where the student simply takes' the difference of the two digits in each column, irrespective of which is the larger. Doing this produces an error in which the student ought to borrow, but does not
The solution of an equation is the value that when substituted for the variable makes the equation a true statement. To achieve our goal, we use two principles of equality, the addition principle and the multiplication principle.
