11 Tips to Solve Math Simple but Extremely Interesting

If you have difficulty solving simple Math problems, then it is not your fault. The problem is that no one teaches you simple but ".

1. Calculate the simple percentage of a number.

To find the percentage of a number (. Eg: 40% of 300 ), we take that number of numbers and the given number divided by 10 then multiply them together and finish (. 4 x 30 = 120 ). Do you know this calculation tip? It's so easy!

2. Calculate squared quickly

This calculation tip can help you find the square of a 2-digit number with the end of 5. First, multiply the first digit of that number by the sum of the first digit plus 1 (. Eg 35², take 3 x (3 + 1) ), then add 25 to immediately produce the result.

3. The 9th multiplication table is extremely easy to remember.

Is the multiplication table 9 the result of which the number of units, as well as the tens, are all numbers from 0 to 9 but opposite?

4. Multiply the numbers by 5.

First, we get the given number divided by 2. If the result is an integer, add the number 0 at the end. If the result is not an integer, ignore the decimal part and add the 5th digit at the end.

5. Multiply the numbers easily by 11.

If you want to multiply a 2-digit number by 11, you just need to separate the two numbers, get the 2-digit sum that is inserted between those 2 digits and be the result. Try it now! For example: multiply 14 x 11, get (1 + 4) = 5, so the result of this multiplication is 154. Is it simple?

6.Simple multiplication with 4

Want to multiply a number by 4 easily, you just need to take that number multiplied by 2 and add it to multiply it by 2 (. Which is actually a distribution ). Try another one: 35 x 4 = (35 x 2) + (35 x 2) = 70 + 70 = 140.

7. Another tip that makes it easy to charge Tips.

If you need to leave 15% of the bill to make Money Tips, there is a fairly simple way to calculate the amount you need to re-send. First, calculate 10% of your bill (. Calculated as item 1 of the article, ie divide the total amount by 10. ), then add 1/2 of the calculated result, which is Money Tips.

8. Difficult multiplication also becomes as easy as chewing candy.

If you need to multiply large numbers by a given number, simply group them into simpler operations than you can get the answer. For example: 64 x 75, first divide 64 by 2 and multiply 75 by 2 => you get 32 x 150 calculation, continue to do so, you get the following operations: 16 x 300; 8 x 600; 4 x 1200; 2 x 2400; 1 x 4800 = 4800.

9. Divide a number by 5.

It is difficult to divide a large number into 5, but it is very simple. All you need to do is multiply that big number by 2 and then move the decimal point left one unit.

10. Subtract 1000 from any number.

There is a fairly easy rule in subtracting 1000: get 9 minus the digits in the minus, separate the last digit, take 10 minus that number, then transplant the results in turn to the last one. Please observe the example on the picture to get a better understanding.

11. Convert Celsius (Celsius) to Fahrenheit (degrees F) and vice versa.

Want to switch from Celsius to Fahrenheit: first you have to multiply that temperature first by 2, then add 30 to. Correctly the formula is to multiply the temperature in degrees C given by 1.8 and add 32, but for quick, simple calculations close to the answer, you can multiply 2 and add 30. For example: 25°C = (25 x 2) + 30 = 80 degrees F (exactly 77 degrees F).

Besides, switching from F to C is the opposite of the above calculation. Take degree F minus 30 then take that result divided by 2. Example 80 degrees F = (80 - 30): 2 = 50: 2 = 25°C.

Refer to some more articles:

• How many people can solve the puzzle "Who is a fisherman?" by Einstein.
• Try solving these 8 puzzles to see how your logical thinking ability works.
• 6 logical puzzles for children that make adults "headache".

Having fun!