School is important, but it doesn’t teach you everything you need to know in life. There are probably many things you learned at school that you are never going to use in real life, so here are some other tricks that are extremely relevant instead.
1. How to calculate how much time is left before sunset
This one is very easy to learn. With your fingers touching, place your left hand up to the sky with the palm facing you. Then, place it so that the bottom of the sun touches the top of your index finger. Now, count the number of fingers it takes to touch the horizon. Each finger gives 15 minutes, so if you have four fingers between the sun and the horizon mean there are 60 minutes left before the sun sets. Three fingers mean 45 minutes are left, and so on.
2. How to tell the number of days in a month
If your parents didn’t tell you this before you even started school, make fists using both your hands. Then, start counting the months using your knuckles and the spaces in between them. If the month lands on a knuckle, it has 31 days. If it lands in the space between, it has 30 or less, like it’s the case with February.
3. How to tell if the moon is waxing or waning
This one is also a piece of cake. You just need to remember these three letters: O, D and C. If the moon looks like an O, it is full. If it looks like a C it is waning, and if it looks like a D, it is waxing.
4. How to remember Roman numerals
In order to remember Roman numerals, keep the following phrase: My Dear Cat Loves Xtra Vitamins Intensely. The first letter of each word in the phrase represents the Roman numerals going in descending order. So, M is 1,000, D is 500, C is 100, L is 50, X is 10, V is 5, and I is 1.
5. How to tell if a battery is still good
This one is indeed practical. Just lift your battery a few centimeters above a table and let it drop. If it bounces and falls, it is empty.
6. How to multiply 6, 7, 8 and 9 using your fingers
Turn both your hands so that your palms are facing you. Assign each finger a number and start with your pinkie. Pinkies represent 6, ring fingers represent 7, middle fingers represent 8, and your indexes are 9s. Your thumbs are 10s. Now, let’s imagine we want to calculate 7×8:
We would touch our left ring finger (for 7) to the middle finger of the right hand (for 8). Now, count the touching fingers and all the fingers beneath them. In this case, we have 5 (the touching middle and ring finger, the ring finger from the right hand, and the two pinkies). These bottom numbers represent 10s, so 5 x 10 is 50.
All the fingers on top of the touching fingers represent 1s, and they need to be multiplied together. In this case, we have 3 top fingers on the left hand and 2 fingers on the right hand (index and thumb). If we multiply them, 3 x 2 is 6.
Then, add the product from the top fingers to the product from the bottom fingers and that’s how you will get the answer, 56.
7. How to multiply the number 9 using your fingers
If you need to multiply a small number by 9, the method is even easier.
First, put both your hands up, with your fingers outstretched. The left pinky finger represents the number 1, the left ring finger represents the number 2. The left middle finger represents the number 3, and so on all the way to 10. Now, let’s imagine you want to multiply 9 by 3. You need to bend the third finger downwards (the left middle finger).
Then, count the fingers to the left and right of the bent finger. In this case, we have 2 on the left and 7 on the right. Next, just put the numbers together, and you get the answer, which is 27.
8. How to quickly measure the degrees of an angle
You can do this using one hand only. First, spread your fingers as much as possible. Next, put your palm down onto the angle you want to measure, with the pinky finger touching the bottom side. Your pinky will represent o°. Now, just see which finger the angle comes closest to: the angle between the thumb and pinky finger is 90°, between pinky and index is 60°, between pinky and middle is 45°, and between pinky and ring is 30°.
9. How to quickly measure distance
As you can see in the image above, measuring distance is pretty easy, once you spread out your palm in the right way.