Exploring Multiplication with Base Ten Blocks
Learn how to model multiplication using base ten blocks for better understanding. Practice with examples of repeated addition and rectangular array models.
Exploring Multiplication with Base Ten Blocks
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Presentation Transcript
Ex. # 1 24 × 3 Instead of modeling 24 × 3, let’s model 3 x 24. You may use the commutative property of multiplication when modeling multiplication with base ten blocks.
Ex. # 1 Repeated Addition Model (cont.)3 × 24 3 × 24 means 3 24’s. 24 is 2 longs and 4 units.
Ex. # 1 Repeated Addition Model (cont.)3 × 24 Join together. I now have 6 longs and 12 units.
Ex. # 1 Repeated Addition Model (cont.)3 × 24 Exchange 10 units for 1 long. I now have 7 longs and 2 units. 3 × 24 = 72, so 24 × 3 = 72.
Ex. # 2 Rectangular Array Model3 × 24 3 × 24 means 3 24’s. 24 is 2 longs and 4 units. Place 2 longs and 4 units in a rectangular array 3 times.
Ex. # 2 Rectangular Array Model (cont.)3 × 24 Count the number of blocks used. There are 6 longs and 12 units. Exchange 10 units for 1 long. There are 7 longs and 2 units. 3 × 24 = 72
Ex. # 3 Rectangular Array Model13 × 12 • Use 1 long and 3 units to outline a rectangle whose width is 13. • Use 1 long and 2 units to complete the outline of a rectangle whose length is 12. • Fill in the rectangle, using as few base ten blocks as possible.
Ex. # 3 Rectangular Array Model (cont.)13 × 12 Count the number of blocks used. There are 1 flat, 5 longs, and 6 units, so the product is 100 + 50 + 6 or 156. 13 × 12 = 156
Ex. # 4 Rectangular Array Model13 × 22 • Use 1 long and 3 units to outline a rectangle whose width is 13. • Use 2 longs and 2 units to complete the outline of a rectangle whose length is 22. • Fill in the rectangle, using as few base ten blocks as possible.
Ex. # 4 Rectangular Array Model (cont.)13 × 22 Count the number of blocks used. There are 2 flats, 8 longs, and 6 units, so the product is 200 + 80 + 6 or 286. 13 × 22 = 286
