Checking Subtraction with Addition
Checking Subtraction with Addition is a Grade 4 math skill in enVision Mathematics, Chapter 2: Fluently Add and Subtract Multi-Digit Whole Numbers. Students verify subtraction answers by adding the difference back to the subtrahend to confirm the sum equals the original minuend.
Key Concepts
Addition and subtraction are inverse operations. To check a subtraction problem, add the difference (the answer) to the subtrahend (the number being subtracted). The sum must equal the minuend (the number you started with). $$a b = c \quad \Leftrightarrow \quad c + b = a$$.
Common Questions
How do you check a subtraction answer with addition?
Add the difference (your answer) to the number you subtracted. If the result equals the original number you started with, your subtraction is correct.
What is the relationship between addition and subtraction?
Addition and subtraction are inverse operations. If a minus b equals c, then c plus b must equal a. This inverse relationship is what makes checking subtraction with addition work.
What is an example of checking subtraction with addition?
To check 8,452 minus 3,276 equals 5,176, add 5,176 plus 3,276. If the sum is 8,452, the subtraction is correct.
Why should you always check your subtraction work?
Subtraction, especially with multiple regroupings, is error-prone. Checking with addition quickly confirms whether you borrowed and subtracted correctly.
What chapter covers checking subtraction in enVision Grade 4?
Checking subtraction with addition is covered in Chapter 2: Fluently Add and Subtract Multi-Digit Whole Numbers in enVision Mathematics Grade 4.