Long Division: Using Standard Algorithm Adapted from 21 st Century Lessons 1

2 Objectives Students will be able to indentify the parts of division problems in various forms. Students will be able to explain and apply multi-digit division using standard algorithm. Students will be able to discuss long division using correct vocabulary.

Vocabulary Algorithm: A formula or set of steps for solving a problem. Division: Splitting of large numbers into equal groups of smaller numbers. Dividend: Number being divided. Divisor: Number you are dividing by. Quotient: Answer to a division problem.

Vocabulary Video

5 On a school field trip, your class followed a treasure map and found a buried treasure! Imagine that your class has 25 students total, and that there were 1000 gold coins in the treasure chest. How many coins does each student get? Express your answer in three different ways. Warm Up

6 Express the problem in three ways. We found 1000 gold coins, and need to divide them equally between the 25 students in our class. _____ 25) = ÷ 25 =

Warm Up 7 So how many coins does each student get? _____ 25) = ÷ 25 = We’ll check back on this problem in a little while!

8 With your partner, list the three ways to express the clam’s division problem.

9 With your partner, list the three ways to express the clam’s division problem: FRACTIONLONG DIVISION ALGORITHM NUMBER SENTENCE

The Steps to Long Division Video

11 How many steps are there in the long division algorithm?

12 How many steps are there?

13 Let’s apply the steps to long division to a new problem: 84 ÷ 6 = ?

Explore 14 DIVIDE MULTIPLY SUBTRACT BRING DOWN

15 Set up the problem: 84 ÷ 6 = ? in the long division algorithm looks like which of the options below? 84 ? ) 6 84 = ? ) ? 6 = ? 84 ? 6) = ? 6 CHOICE A CHOICE B CHOICE C ✗✗

16 8 ÷ 6 = STEP ONE: DIVIDE We divide the dividend by the divisor. 1 Follow along with the Guided Practice Worksheet! 1

17 6 x 1 = STEP TWO: MULTIPLY We multiply 6 6

18 STEP FOUR: BRING DOWN We bring the 4 down 4

19 8 – 6 = STEP THREE: SUBTRACT We subtract 2 2

20 NOW WHAT???

21 24 ÷ 6 = STEP ONE: DIVIDE We divide 4 4

22 6 X 4 = STEP TWO: MULTIPLY We multiply 24

23 24 – 24 = STEP THREE: SUBTRACT We subtract 0 0

24 STEP FOUR: BRING DOWN There is no number to bring down – we’re almost DONE!

25 Don’t forget to check your answer! The opposite of 84 ÷ 6 = 14 is 6 X 14 =

26 Checking your answer x 6

Practice 1 27 Let’s try one more problem – try it alone and we’ll review it together! What do these number sentences look like in the long division algorithm? ? 12) ÷ 12 = ? = ?

Practice ÷ 12 = STEP ONE: DIVIDE What are we dividing? 1 We are dividing the dividend by the divisor. 1

Practice X 1 = STEP TWO: MULTIPLY We multiply 12

Practice – 12 = STEP THREE: SUBTRACT We subtract 2 2

Practice 1 31 STEP FOUR: BRING DOWN We bring down 4

Practice 1 32 NOW WHAT???

Practice ÷ 12 = STEP ONE: DIVIDE We divide the dividend by the divisor. 2 2

Practice x 2 = STEP TWO: MULTIPLY We multiply 24

Practice = STEP THREE: SUBTRACT We subtract 0 0

Practice 1 36 STEP FOUR: BRING DOWN There is no number to bring down – we’re almost done!

Practice 1 37 Don’t forget to check your answer! The opposite of 144 ÷ 12 = 12 is 12 X 12 =

Practice 1 38 Checking your answer x 12

Exit Ticket 39 So how many coins does each student get? _____ 25) = ÷ 25 = Show your work using the long division algorithm.

Exit Ticket 40 So how many coins does each student get? Each student gets gold coins! 40

Summary 1. How many steps are there to the long division algorithm? What are they? 2. What is the trick the video taught us to remember the steps? 3. Is there anything confusing about using the long division algorithm? 41

42 Credits Original lesson designed by Catherine Murphy & Sarah Kelly. 21 st Century Lessons. Funded by the American Federation of Teachers. Retrieved from