Multiplying decimal numbers by 10, 100, 1000... (1/2) #mathematics #maths #math #mathstricks

Ajouté : 2026-05-28

[00:00:05]Welcome. Well, in this lesson, we will see how to multiply decimal numbers by 10, 100, 1,000.

[00:00:13]In particular, we will analyze cases where the number of digits after the decimal point of the first factor is less than the number of zeros of the second factor. Let's start with the product 4.7 % * 100.

[00:00:29]As is known, due to the presence of two zeros in the factor 100, the decimal point of the factor 4.7 should be moved two positions to the right. However, we observe that after the decimal point, the factor 4.7 has only one digit, so we can move the decimal point only one position.

[00:00:49]To complete the operation, it is necessary to add it a zero, resulting in 470.

[00:01:00]Let's consider another example, 14.23 * 1,000. In this case, the decimal point of it the factor 14.23 should be moved three positions to the right, corresponding to the number of zeros in the factor 1,000.

[00:01:17]Since the digits after the decimal point of the factor 14.23 are only two, it will be necessary to complete the operation by adding a zero at the end, resulting in 14,230.

[00:01:33]Again, let's consider the product 0.4 % the decimal point of the factor of the factor 0.4 must be moved two positions to the right, but after the decimal point, we have only one digit, so in this case, it is also necessary to add a zero at the end.

[00:01:54]The The would be 0.4, and as is known, the zero in the first position has no weight and can be eliminated, thus obtaining 40 as the result.

[00:02:12]Again, let's consider the product 2.6 * 1,000. The dot The decimal point of the factor 2.6