The speaker demonstrates an easy method to multiply numbers without a calculator or multiplication table. This method is based on a modified Japanese technique. To multiply numbers, the speaker draws lines to represent the numbers, with the number of lines corresponding to the digits. The intersection points of the lines are counted to find the product.
The method is shown to work for single-digit, two-digit, three-digit, and four-digit numbers, as well as for numbers with zeros. The speaker provides several examples, including multiplying a three-digit number by a two-digit number, and a four-digit number by a two-digit number.
In each example, the speaker draws the lines to represent the numbers, divides the drawing into areas, and counts the intersection points to find the product. The method is shown to be accurate and efficient, and the speaker encourages viewers to try it out and share their experiences.
Some key takeaways from the video include:
* Drawing lines to represent the numbers, with the number of lines corresponding to the digits.
* Dividing the drawing into areas and counting the intersection points to find the product.
* Representing numbers with zeros by drawing a red dotted line.
* Mentally writing down a two-digit number as a four-digit number when multiplying a four-digit number.
* Avoiding leading zeros when rewriting the numbers from left to right.
Overall, the speaker presents a unique and effective method for multiplying numbers without a calculator or multiplication table.
Here are the key facts extracted from the text:
1. The method of multiplying numbers without a calculator is based on a modified Japanese method.
2. The method involves drawing lines to represent the numbers being multiplied.
3. For single-digit numbers, the method involves drawing lines at an angle and counting the intersection points.
4. For multi-digit numbers, the method involves drawing lines to represent the tens and units digits.
5. When multiplying numbers with zeros, the method involves drawing a dotted line to represent the zero.
6. The method involves dividing the drawing into areas and counting the intersection points in each area.
7. The resulting numbers are written from left to right, with each digit corresponding to an area.
8. The method can be used to multiply single-digit, two-digit, three-digit, and four-digit numbers.
9. The method can be used to multiply numbers with zeros.
10. The method is based on the concept of intersection points, which represent the product of the numbers being multiplied.
11. The method can be used to multiply numbers of different lengths, such as a three-digit number by a two-digit number.
12. The method involves adding zeros to the shorter number to make it the same length as the longer number.
13. The method can be used to multiply four-digit numbers by two-digit numbers.
14. The method can be used to multiply four-digit numbers by other four-digit numbers.