3 tips by hand 'like hacking' worth sending to the future

I don't know when, but these tips still prove useful until today.

Do not know when to appear, but people have created a lot of recipes, tips to show the usefulness until today (and maybe forever after).

3 of them will be listed right here. Let's learn about "hacking" calculation tips to make your life easier than ever.

1. Measure the length in the fastest way

The average distance between the thumb and forefinger is 18cm, and the pinky is 20cm.

In case you want to measure something without a ruler, you can use your own hands as a tool. According to some surveys, the average distance between the thumb and forefinger is 18cm, and the pinky is 20cm.

Of course, this method is only an estimation but not absolutely accurate, because it depends on the size of each person's hand. If you want to be more accurate, you can . measure your hands in your free time, so that you can use them later.

2. Measure the angle in 5s

The angle created by the little finger and thumb is 90 degrees, and turns 60 degrees with the index finger, 45 degrees the middle finger, 30 degrees the ring finger.

Similarly, the hand is still a very useful tool when you want to measure the angle of a certain triangle.

Stretch your hands all the way, placing your palms on the flat surface so that the pinky finger is on the bottom edge. At this time, the angle created by the little finger and thumb is 90 degrees, and turn 60 degrees with the index finger, 45 degrees the middle finger, 30 degrees the ring finger.

3. How do I know how many days this month has?

One year has 12 months and 365 days. But 365 can't be divided by 12, so the number of days in each month is different.

To know how many days the current month is, you . can view the calendar. But actually there is a simpler way like that, right in the picture below!

Month is on convex joints, that month has 31 days.If lying in the dent is 30.

Looking a little confusing, right? It's really easy. Hold your fist into a fist, you will see the back of your hand appear concave and concave made up of hand joints. Each convex, concave represents the month.

If the month is on the convex joint, that month has 31 days. If the dent is located at 30. It is 28 or 29 days in February.

Months will be counted in turn (left or right through). August will be in the same position as July, then reverse, still follow the same rules.