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Continuing the Conversation. Continuing the Conversation. Cathy Fosnot. Minilessons for Multiplication and Division. A warm–up mental math string. 100 x 13 2 x 13 102 x 13 99 x 13 14 x 99 199 x 34. What strategy does this string support? What big ideas underlie this strategy?.
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Continuing the Conversation Cathy Fosnot
A warm–up mental math string • 100 x 13 • 2 x 13 • 102 x 13 • 99 x 13 • 14 x 99 • 199 x 34 • What strategy does this string support? • What big ideas underlie this strategy?
Small Group Discussions • What strategies would you expect to see? • How would you represent them?
How many apples? How many lemons? • Count by ones • Skip count • 2 x 6 = 4 x 3 = 6 x 2 • 2 x 9 = 2 x 3 x 3 = 6 x 3 • Associative property
How many tiles in each patio? • The furniture obscures some of the tiles possibly providing a constraint to counting by ones and supporting the development of the distributive property
Let’s go to a classroom… Cdrom, minilesson folder (first), 3rd page Video clip #53
Did anyone try minilessons like these, with pictures? Did you find any nice pictures in magazines that you could use?
Grade 4 • 6 x 8 • 12 x 8 • 12 x 4 • 24 x 2 • 3 x 16 • 18 x 50 • What’s the focus of the string? • A) doubling and halving • B) associative property • C) distributive property • D) using friendly numbers
How could you show doubling and halving strategies on an array?
Let’s go to a classroom… Cdrom, minilesson folder (first), 1st page Video clip #16
Grade 4 • 170 / 17 • 34 / 17 • 204 / 17 • 357 / 17 • 323 / 17 • What’s the focus of the string? • A) distributive property for multiplication • B) partial quotients • C) simplifying • D) A and B
For the last problem, 323/17, if a child said I got 19 because I took 17 away from 340, how would you represent that using an open array?
20 -1 17 340 -17
Let’s go to a classroom… Cdrom, minilesson folder (second), 3rd page Video clip #330
Has anyone tried a minilesson like this? Any struggles with representing?
Grade 5 • 100 / 4 • 200 / 4 • 200 / 8 • 400 / 16 • 800 / 32 • 300 / 12 • 900 / 18 • What’s the focus of the string? • A) distributive property • B) simplifying • C) splitting • D) using landmark numbers
Folder 2, page 5 Clip 236