Twenty Objects Trick

1. Place 20 objects on the overhead.2. Have a student remove any number of items from 1 to 10.3. The items that remain will be a two-digit number.4. Have a student find the sum of these two digits and remove that many more items from the projector.5. Have a student give you some of the remaining objects.6. You should subtract that number from 9 and tell her how many objects

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The Dictionary Trick

This is my favorite trick. A student of mine from Herndon High School in Fairfax County, Virginia showed this to me in the late 1960s, and I used it nearly every year after that until I retired in 2006.Ask a student to pick a three digit number (where the first and last digits are different).Then have the student reverse the digits and subtract the two numbers.Give the student a dictionary,

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Phone Number Trick

1. Get a calculator. (You won't be able to do this one in your head)2. Key in the first three digits of your phone number (NOT the area code)3. Multiply by 804. Add 15. Multiply by 2506. Add the last 4 digits of your phone number7. Add the last 4 digits of your phone number again.8. Subtract 2509. Divide number by 2Do you recognize the answer?Explanation:Let x= 1st three digits

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PERCENTAGE CALCULATION

Calculate 65% of 460:50% of 460 = 23010% of 460 = 465% of 460 = 23 (half 46)------------------------------65% of 460 = 299 (sum)EXAMPLE.Calculate 67.5% of 460:50% of 460 = 23010% of 460 = 465% of 460 = 23 (half 46)2.5% of 460 =11.5 (half 23)------------------------------67.5% of 460 = 310.5 (sum ) < Comment down if it's Helpful

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