Solve problems involving multiplication of large numbers by one- or two-digit numbers using efficient mental, written strategies and appropriate digital technologies (VCMNA183)
LO: To multiply large numbers
Know:
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Multiplication facts up to 10 x 10
Understand:
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multiplying numbers by whole numbers increases the value of a number.
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dividing numbers by whole numbers decreases the value of a number.
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Dividing can be thought of as “evenly dividing”
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Dividing is the opposite of multiplying
Do:
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I can multiply large numbers and solve related problems.
Times Tables
Grid Method
Step 1: break 45 and 23 into their respective parts.
Step 2: write 40 and 5 at the top, 20 and 3 down the side.
Step 3: multiply 40 x 20 then 5 x 20 then 40 x 3 and 5 x 3
Step 4: Then add all of the sums together
Lattice Method
Step 1: Break down the numbers to their respective parts.
Step 2: write 2, 7, 8 at the top and 3 and 4 down the side
Step 3: split each of the cells into halves diagonally.
Step 4: work out each box accordingly, 8 x 3, 7 x 3, 2 x 3, 8 x 4, 7 x 4, 2 x 4
Step 5: add all numbers below each line
Step 6: Circle the outside numbers and re-write answer.
Long Multiplication
Step 1: Set up the “tower”
Step 2: multiply the first number accordingly 6 x 3, 6 x 5
Step 3: Don’t forget the “magic zero”
Step 4: multiply the second number accordingly 2 x 3, 2 x 5
Step 5: Add the numbers column by column
Multiplying Using Lines
