If multiplication repeated addition then division Relate Subtraction
If… multiplication = repeated addition then, division = ______
Relate Subtraction to Division If multiplication is repeated addition, then division is repeated subtraction.
Let’s Model Division Chris has $12 for the book fair. Each book he wants to buy cost $4. How many books can Chris buy?
Let’s Model Division Chris has $12 for the book fair. Each book he wants to buy cost $4. How many books can Chris buy? 12 $ -4 4 8 Chris buys one book, spends $4, and has $8 left. Can he buy another book?
Let’s Model Division Chris has $12 for the book fair. Each book he wants to buy cost $4. How many books can Chris buy? 8 12 $ $ -4 -4 4 8 Chris buys another book, spends another $4, and has $4 left. Can he buy another book?
Let’s Model Division Chris has $12 for the book fair. Each book he wants to buy cost $4. How many books can Chris buy? 4 8 12 $ $ -4 -4 -4 4 4 0 4 8 $ 4 Chris buys another book, spends another $4, and has $0 left. Can he buy another book?
Let’s Model Division Chris has $12 for the book fair. Each book he wants to buy cost $4. How many books can Chris buy? 4 8 12 $ $ -4 -4 -4 4 4 0 4 8 $ 4 Chris spent $4 three times. He subtracted $4 three times. So, 12 ÷ 4 = 3. He can buy 3 books.
Let’s Model Division Again Pedro has 15 books he wants to put equally on bookshelves. He has 3 bookshelves. How many books can go on each shelf?
Let’s Model Division Again Pedro has 15 books he wants to put equally on bookshelves. He has 3 bookshelves. How many books can go on each shelf? 15 -3 1 2 So far, he has put 1 book on each shelf. He has 12 books left. Can he put another book
Let’s Model Division Again Pedro has 15 books he wants to put equally on bookshelves. He has 3 bookshelves. How many books can go on each shelf? 15 -3 1 2 12 -3 9 So far, he has put 2 books on each shelf. He has 9 books left. Can he put another
Let’s Model Division Again Pedro has 15 books he wants to put equally on bookshelves. He has 3 bookshelves. How many books can go on each shelf? 15 -3 1 2 12 -3 9 9 -3 6 So far, he has put 3 books on each shelf. He has 6 books left. Can he put another
Let’s Model Division Again Pedro has 15 books he wants to put equally on bookshelves. He has 3 bookshelves. How many books can go on each shelf? 15 -3 1 2 12 -3 9 9 -3 6 6 -3 3 So far, he has put 4 books on each shelf. He has 3 books left. Can he put another
Let’s Model Division Again Pedro has 15 books he wants to put equally on bookshelves. He has 3 bookshelves. How many books can go on each shelf? 15 -3 1 2 12 -3 9 9 -3 6 6 -3 3 So far, he has put 5 books on each shelf. He has 0 books left. Can he put another 3 -3 0
Let’s Model Division Again Pedro has 15 books he wants to put equally on bookshelves. He has 3 bookshelves. How many books can go on each shelf? 15 -3 1 2 12 -3 9 9 -3 6 6 -3 3 Pedro can put 5 books on each shelf. The division sentence is 15 ÷ 3 = 5 3 -3 0
Let’s use a Number Line Pedro has 15 books he wants to put equally on bookshelves. He has 3 bookshelves. How many books can go on each shelf? 15 -3 1 2 12 -3 9 9 -3 6 6 -3 3 3 -3 0
Let’s use a Number Line Pedro has 15 books he wants to put equally on bookshelves. He has 3 bookshelves. How many books can go on each shelf? 15 -3 1 2 12 -3 9 9 -3 6 6 -3 3 Pedro can put 5 books on each shelf. The number line shows 3 -3 0
To write a division sentence from a repeated subtraction sentence…
To write a division sentence from a repeated subtraction sentence… • The dividend is your total or starting number. 12 12 ÷
To write a division sentence from a repeated subtraction sentence… • The dividend is your total or starting number. 12 • The divisor is the number you are subtracting. 2 12 ÷ 2
To write a division sentence from a repeated subtraction sentence… 1 2 3 4 5 6 • The dividend is your total or starting number. 12 • The divisor is the number you are subtracting. 2 • Your quotient is how many times you 12 ÷ 2 = 6 subtracted until you got to zero. 6
How is division related to subtraction?
Exit Ticket Solve the problem below using repeated subtraction: 18 ÷ 6 = __ Solve the problem below using any strategy: 18 ÷ 2 = __
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