Amazing Wizard Tricks You Can Do With Basic Math

### Author Topic: Amazing Wizard Tricks You Can Do With Basic Math  (Read 741 times)

#### Masuma Parvin

• Sr. Member
• Posts: 323
##### Amazing Wizard Tricks You Can Do With Basic Math
« on: April 17, 2017, 12:18:38 PM »
Here are a few easy but impressive tricks that you can use to intimidate your friends and amaze your enemies.

1.Perfectly Sort Coins Without Looking at Them:
The Magic is :

Let's start with a trick a moron could do. Let's say we're using a handful of coins. First you close your eyes (or get blindfolded) and tell your spectators to shake up the coins and throw them on the table. All you need is one piece of information: how many of the coins are facing heads-up.Then, without ever peeking at the coins, you sort them into two piles, blindly flipping and shuffling them as if your hands were being guided by the spirit world. You magically wind up with the exact same number of heads in each pile. Every time.

The Math:

Let's say your spectators tell you that there are six heads-up coins in the pile. All you need to do is grab that number of coins and flip them. Just any six random coins. Take the ones you flipped and move them to their own pile, which we'll call Pile #1. The remaining coins are Pile #2. Both piles will contain the same number of heads.

#### Masuma Parvin

• Sr. Member
• Posts: 323
##### Re: Amazing Wizard Tricks You Can Do With Basic Math
« Reply #1 on: April 17, 2017, 12:26:44 PM »
Quickly Calculate the Weekday for Anyone's Birthday

The Math:

You don't have to be very smart to calculate the day of the week for any date -- not when eminent mathematician John Conway already devised a clever shortcut for that, which he (somewhat overdramatically) named the doomsday rule. Crack open a 2014 calendar and you'll see that 4/4, 6/6, 8/8, 10/10, and 12/12 all land on the same weekday: Friday. The same goes for other easy-to-remember dates like 5/9 and 9/5, 7/11 and 11/7, the last day of February, Pi Day, July 4, Halloween, and Michael Jackson's birthday (August 29, as you know). Again, all Fridays.

In 2013, those were all Thursdays:In 2012, they were all Wednesdays. Starting to notice a pattern? Since 2012 was a leap year, in 2011 the "doomsday" jumped to a Monday:And so on. So, let's say you're trying to find out the day of the week for July 9, 1987. First you have to figure out the doomsday for that year, by using an important world event as a point of reference, for example. As you probably learned in history class, Captain EO came out on Friday September 12, 1986, so from there it's easy to calculate that 9/5 was a Friday, too. If 1986's doomsday was a Friday, then 1987's was a Saturday, which makes July 4 of that year a Saturday as well. Therefore, a quick finger count tells us July 9, 1987 was ... a Thursday.