Why does 78 minus your age plus 40 work?

Asked By: Jhonattan Yadrennikov | Last Updated: 5th January, 2020
Category: events and attractions birthday
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How does 78 minus your age plus 40 equal the last two digits of your birth date? Transpose the instructions and add 40 to 78 first. This gives you 118, the number of years that have elapsed since this day in 1900 (today is July 25, 2018). Subtracting this from 118 gives 80, the junior two digits of your year of birth.

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Regarding this, why does 79 minus your age plus 40 work?

79+40=119. That's the number of years from 1900 to 2019. Subtract your age from 119 and you'll get the year you were born. It only works well at the end of the year however, because at that point, most people will have had a birthday in the current year.

Secondly, how do you figure out someone's age trick? To do a number trick to guess someone's age, start by asking them to use a calculator to multiply the first number of their age by 5. Then, have them add 3 before doubling the answer. Next, they should add the second number of their age. Finally, tell the person to subtract 6 and the answer will be their current age.

Subsequently, one may also ask, how does the birthday math trick work?

"Threes" Birthday Math Trick

  • Enter the secret number.
  • Multiply by 3.
  • Add the secret number, then subtract 5.
  • Multiply by 3, then multiply by 3 again.
  • Add the secret number, then subtract the number of their favourite month (you don't have to know what month that is!)
  • Multiply by 3, then multiply by 3 again, and then again a third time.

What is it called when you are the same age as the year you were born?

A Beddian Birthday occurs when the age a person is turning, is the same number as the last two digits of their birth year. The Beddian birthday is named for NYC firefighter Bobby Beddia who noted this coincidence. Someone born in 2015, will experience their Beddian Birthday when they are 15!

31 Related Question Answers Found

How do you manually calculate age from date of birth?

To calculate age manually is a fairly simple arithmetic procedure. The process of calculating age involves comparing one's birth year with the year in which age needs to be calculated. First of all, the current ongoing year is taken note of. After that, the year of birth is considered.

Is everyone the same age in 2019?

It's amazing: this year all the people in the world are all in the same age group, all equal to 2019. This year is special. It happens only once every 1,000 years. This year your age + your year of birth, each individual is = 2019.

How can you tell someone's age without asking?

Here are 15 ways to find out how old your date really is without actually asking:
  1. Stalk him on social media. Social media is always a go-to.
  2. Ask mutual friends.
  3. Check LinkedIn.
  4. Google him.
  5. Search public records and data.
  6. Analyze his name.
  7. Bring up technology.
  8. Discuss school memories.

How do I calculate my birthday number?

  1. Begin with your full birth date.
  2. Reduce the month, day and year down to a single digit by adding them.
  3. Now add the resulting single digits together to get the Life Path Number.
  4. Begin with your full birth date.
  5. Reduce the month, day and year down to a single digit by adding them.

What is the calculator trick?


The Secret of 73
Write the number 73 on a piece of paper, fold it up, and give it to an unsuspecting friend. Tell your friend select a four-digit number and enter it twice into a calculator. Inform your friend that the number is divisible by 137 and ask him or her to verify using the calculator.

How do you figure out birthdays?

Some phrases you can try out are:
  1. Have a wonderful birthday!
  2. Hope your special day is amazing!
  3. Hope you have an enjoyable birthday! You deserve it.
  4. I'm so glad to know you and hope you have an amazing day.
  5. Enjoy your next trip around the sun!

How do you do the number trick?

Perform the trick:
  1. Think of a number, any positive integer. Keep it small so you can do computations in your head.
  2. Square it.
  3. Add the result to your original number.
  4. Divide by your original number.
  5. Add, oh, how about 17.
  6. Subtract your original number.
  7. Divide by 6.
  8. The number you are thinking of now is 3!

Can u guess my birthday?

“ I can Guess your birthday”: Multiply the number of the month in which you were born by 5. Add the number of the day on which you were born.

What year were you born if you are 8 years old?

Your child's year group
Date of birth School year 2019-2020 Age
September 2003 - August 2004 Year 11 15 - 16
September 2004 - August 2005 Year 10 14 - 15
September 2005 - August 2006 Year 9 13 - 14
September 2006 - August 2007 Year 8 12 - 13

How can you tell what number someone is thinking of?


Once your friend has chosen a number, follow these steps:
  1. Tell him to multiply the chosen number by 2.
  2. Choose an even number to use yourself. Ask your friend to add this number to the one in his head.
  3. Tell him to divide the new number by 2.
  4. Tell him to subtract his original number from the equation.
  5. "Guess" the number.

How can you guess someone's shoe size?

The trick involves asking someone to write down their shoe size without telling you. They must then multiply the figure by 5, add 50, multiply that number by 20, add 1015, and subtract the year of their birth.

How can you tell a girl's age without asking?

Here are a few ways to know her age without offending her (if she seems offended at it, that is!).
  1. Get her to be your friend in Facebook.
  2. Ask for her email.
  3. Ask her which school she was from.
  4. Ask her when she graduated and started her first job.
  5. LinkedIn search her.
  6. Google her.

What is your real age test?

The Real Age Test
Taken by more than 45 million people, the scientifically-based assessment shows you the true age of the body you're living in – the first step towards improving your well-being. The test was created by top doctors, including Dr. Oz and Dr. Mike Roizen, and is powered by the latest medical research.

How do you respond when someone asks your age?

A few suggestions:
  1. Say politely but as if confused: “Why do you want to know that?”
  2. Laugh and say: “Old enough to know better than to answer that question.”
  3. Say “How old do you think I am?
  4. Say what we did as kids: “Same age as last year but a year older.”
  5. Pretend you didn't hear.
  6. Say nothing and stare at them blankly.

What is your age Google?


You can follow these steps to verify your age in your Google account: Sign into your Google account privacy page on a computer. Under the "Personal info & privacy" section on the side menu, click Your personal info. Click Birthday.

Is it rude to ask someone their age?

In short, you should know that asking someone's age is rude, so you should not ask. If someone does ask you, know that it is completely proper for you to say something like, "That is not information that I wish to share.

How can you tell age by face?

There actually are simple So basically you can guess age by skin firmness, lack of lines, plumpness and low amounts of photo or sun damage. So this is how it works .

  1. Get your age.
  2. Get the age you feel you have.
  3. Subtract Current Age - Felt Age = X.
  4. Guess the person's age.
  5. Add X.