Essential Questions:
LP 5.NBT.B.5-7 Multiplying Decimals to Hundredths
Lesson Seed B.5: Standard Algorithm for Multiplication Based on Place Value
Lesson Seed B.7: Addition & Subtraction with Decimals
Unit Overview
Content Emphasis By Clusters in Grade 5
Progressions from Common Core State Standards in Mathematics
Send Feedback to MSDE’s Mathematics Team
Lesson seeds are ideas that can be used to build a lesson aligned to the CCSS. Lesson seeds are not meant to be all-inclusive, nor are they substitutes for instruction. When developing lessons from these seeds, teachers must consider the needs of all learners. It is also important to build checkpoints into the lessons where appropriate formative assessment will inform a teachers instructional pacing and delivery.
Standard(s): 5.NTB.b.5 Fluently multiply multi-digit whole numbers using the standard algorithm.
Purpose/Big Idea: To understand why the standard algorithm works based using place value for multiplication.
Materials
Activity:
Exploration
Area Model
Standard Algorithm Explained Using Place Value 15 X 23 45 (3 x 5) + (3 X 10) = 15 + 30 = 45 300 (20 x 5) + (20 x 10) = 100 + 200 = 300 345
Games to build fluency:
2. Four Tiles http://www.shodor.org/interactivate/activities/ArithmeticFour/ Students play an interactive game where correct answers allow them to place a tile on the board. The first person to get four tiles in a row wins.
3. Product War
Player 2 wins all 8 cards. Guiding Questions: