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TUTORIALS:
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Multiplying by 572
To multiply a multiple of 7 by 572, perform the following:
• Divide the number by 7.
• Multiply the number by 4.
• Write the result on the right, using three digits. Then
write the result on the left.
Example:
21 × 572 =
Solution:
• 21 ÷ 7 = 3
• 3 × 4 = 8
• Write 008 as 8 is the result and you must use
three-digits. Then write the 8 on the left. The final answer is
8008.
Answer:
21 × 572 = 8008.
Example:
84 × 572 =
Solution:
• 84 ÷ 7 = 12
• 12 × 4 = 48
• Write 048 on the right (using three digits). Then write
48 on the left. The final answer is 48048.
Answer:
84 × 572 = 48048.
Note: This trick works because 
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