Long Division: Checking Your Work

Contributor: Meghan Vestal. Lesson ID: 11809

Working hard to solve a problem without checking your work is not a good idea. What if you were designing a rocket or serious medical device? Learn the easy, strategic way to check your long division!

categories

Elementary

subject
Math
learning style
Visual
personality style
Lion, Beaver
Grade Level
Intermediate (3-5)
Lesson Type
Skill Sharpener

Lesson Plan - Get It!

Audio:

How can you check to see if the following problem has been solved correctly without re-solving the problem?

There are many steps to solving a long division problem — that means there is a lot of room for error.

In the previous Related Lesson in our Long Division series, found in the right-hand sidebar, you learned how to check your work while you are solving. Tell your teacher or parent how you can check your work as you solve a long division problem.

In addition to checking your work while you solve, there is a simple way to check your work when you are finished solving.

To find out if you have correctly solved the problem, multiply the quotient (the answer) by the divisor (the number outside the division sign). If the product is the same as the dividend (the number inside the division sign), you have solved correctly. If the product is not the same as the dividend, you have done something wrong and need to resolve the problem.

Using this strategy, check the problem at the beginning of the lesson. Tell your teacher or parent whether or not the quotient is correct.

After checking, you should have found the problem was solved incorrectly (5 x 81 = 405). Solve the problem and then check your answer using the strategy discussed in this section. Show your teacher or parent when you have found the correct answer.

You should have found 83 is the correct answer (5 x 83 = 415). Tell your teacher or parent whether or not you find this strategy helpful and explain your response.

Then, move on to the Got It? section to check some more problems.

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