P.S. 42 Multiplication Strategies Grade 3, 4, 5 Parents Objectives Participants will: *  Gain a deeper understanding of multiplication strategies *  Make connections between various multiplication strategies *  Apply various multiplication strategies to solve word problems Agenda *  Turn and Talk *  Multiplication Strategies *  Decompose & Distribute *  Area Model *  Place Value Strategies *  Distributive Property Turn and Talk Decompose to become broken down into components broken down into separate parts Math the process of separating numbers into their components (to divide a number into smaller parts). . Distribute give shares of (something); deal out; dispense separate or break something into parts Math multiply a sum by multiplying each addend separately and then add the products. 4 X 6 Decompose and Distribute 4 X (5 + 1)
(4 X 5) + (4 X 1)
20
+
4
20 + 4 = 24
4 X 5
4 X 1
4 x 6 Area Model 4
4 X 5
4 X 1
5
1
20
4
Solve 4 x 6 = Turn & Talk Decompose & Distribute? The Distributive Law says that multiplying a number by a group of numbers added together is the same as doing each multiplication separately Example: 3 × (2 + 4) = 3×2 + 3×4 So the "3" can be "distributed" across the "2+4" into 3 times 2 and 3 times 4. Third Grade CCLS: Multiplication 3.OA.5 Apply properties of operations as strategies to multiply and divide: Commutative, Associative, Distributive 3.MD.7c Use area models to represent the distributive property in mathematical reasoning Try It Out! What are Some Ways We Can Solve 8 X 7? Fourth Grade CCLS: Multiplication Use place value understanding and properties of operations to perform multi-­‐digit arithmetic. 4.NBT.5 Multiply a whole number of up to four digits by a one-­‐digit whole number, and multiply two two-­‐digit numbers, using strategies based on place value and the properties of operations. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models. * What is Expanded Notation? * How Does it Connect to Place Value? * How Does it Connect to Decomposing? For Example: 275 Write in Expanded Form or Decompose according to Place Value 2 hundreds + 7 tens + 5 ones OR 200 + 70 + 5 Fourth Grade Multiplication Word Problem Solve using one or more of the following: *  Decomposing *  The Distributive Property *  Area Model *  Place Value A maze at the county fair is made from 275 bales of hay. The maze at the state fair is made from 4 times as many bales of hay. How many bales of hay are used for the maze at the state fair? Fourth Grade Multiplication Word Problem Distributive Property 4 X (200 + 70 + 5) (4 X 200) + (4 X 70) + (4 X 5) 800 + 280 + 20 = 1,100 Fourth Grade Multiplication Word Problem Area Model 4 200 70 5 800 280 20 (4 X 200) + (4 X 70) + (4 X 5) 800 + 280 + 20 = 1,100 Partial Products 4 200 70 5 800 280 20 275 X 4 800 280 + 20 1,100 Applying What We Know… Try It Out! The gift shop at the animal park orders 54 boxes of toy animals. Each box has 12 toy animals. How many toy animals does the shop order? Area Model 50 10 2 4 50 X 10 10 X 4 500 40 2 X 50 100 4 X 2 8 500 100 40 + 8 648 Partial Products 10 2 50 4 50 X 10 10 X 4 500 40 50 X 2 100 4 X 2 8 54 X 12 500 40 100 + 8 648 Distributive Property 50 10 10 X 50 500 4 10 X 4 40 54 X 12 (50 + 4) x (10 + 2) (50 X 10) + (50 X 2) + (4 X 10) + (4 X 2) 2 2 X 50 100 2 X 4 8 500 + 100 + 40 + 8 = 648 Fifth Grade Standards CCSS.Math.Content.5.NBT.B.6: Find whole-­‐number quotients of whole numbers with up to four-­‐digit dividends and two-­‐digit divisors, using strategies based on place value, the properties of operations, and/or the relationship between multiplication and division. Illustrate and explain the calculation by using equations, rectangular arrays, and/or area models. CCSS.Math.Content.5.NBT.B.7: Add, subtract, multiply, and divide decimals to hundredths, using concrete models or drawings and strategies based on place value, properties of operations, and/or the relationship between addition and subtraction; relate the strategy to a written method and explain the reasoning used. Twilight Practice Solve a multiplication problem using one of the following: Decomposing Factors Area Model Distributive Property Partial Products