Lesson: Checking Two-Digit Subtraction Problems by Adding Mathematics • 2nd Grade
In this lesson, we will learn how to use addition to check subtraction and identify the related addition equation that can be solved to check the answer.
Look at the expression .
Choose a strategy and solve the expression.
Hint: You can use the vertical column method.
Check your answer using the inverse operation. Remember that inverse means the opposite.
Which addition expression shows the opposite calculation you need to carry out?
Charlotte and Liam have been asked to solve .
Charlotte solves it and gets an answer of 51.
Liam solves it and gets an answer of 31.
Who is correct? Use the vertical column method to find out.
Check your answer using the inverse operation.
What number do you add to 45 to get 96?
If you know that , find the total of without calculating.