These fast and standard calculation tips will help you a lot when you don't have a computer!
If someone else quickly calculates the multiplication of two two-digit numbers, such as 23 x 12 without allowing you to use the computer, you will not hesitate to take out the pen and set the calculation in a vertical line as well. learn from childhood?
This calculation can take you 1-2 minutes, but with the Japanese mental math tips below, you will not need to put a pen and take too long to multiply the two-digit number. Make sure you enjoy it!
Way 1
Example: You need to find the result of the 23 x 12 multiplication calculation , follow these steps!
Step 1: Show two-digit numbers by straight lines.
Step 2: Count the intersection points between the straight lines and record the results.
The number of intersection points in the bottom right corner will be the result of the unit row.
The number of intersection points in the top left corner is the result of hundreds.
And the total number of intersections in the other two corners will be the last " unknown " you need to find.
If you're not sure, watch the video below!
The video shows how to calculate the number of 2.3-digit numbers.
The result of " scooping up " when you set a vertical calculation!
What if I want to multiply a 3-digit number with a 2-digit number ? Please do the same!
After watching this video, you are no longer afraid of " any calculation "!
Method 2
If you see a straight line that will make you " confused ", then come to this " extreme " way.
Step 1: Draw a square with the number of columns and lines corresponding to the number you have to perform multiplication. Then remember to cross out the boxes!
Step 2 : Perform multiplication in turn of each number in hundreds, tens, units in the first factor with each 2nd factor.
Step 3: Now you just need to add the numbers in the diagonal row to get the result!
Method 3:
Want to multiply two-digit numbers between 10-20, for example: 13 x 14 - we just need to follow the steps as follows:
Step 1: Get the ones' place digits of the two numbers multiplied.
4 x 3 = 12
Step 2: Take a number plus the ones' place digit of the remaining number, get an extra number 0 after that.
(14 + 3) and follow 0 behind that = 170
Step 3 : Adding the results of the two steps above will find the final answer.
12 + 170 = 182.
Example: 14 x 13 = 4 x 3 + (14 + 3) 0 = 12 + 170 = 182
Very fast and not even need to calculate drafts, right? Now you can quickly calculate the calculations. Let's test you around calculations and see who gets the answer faster!
