Riley told his mom that multiplying whole numbers by multiples of 10 was easy because you just count zeros in the factors and put them in the product...
7,000 x 600 = 4,200,000
Riley's mom said this strategy will not always works? Why not? Give example
You have to watch out for extra factors of 10, which add zeroes to the product.
40 x 50 ≠ 200
but if you are counting the zeros and adding it to the numbers in front that have already been multiplied, then he is correct you dont have to remember anything other than multiply anything thats not a zero and then add the zeros to it. so it will always work
Because you have to watch out for extra factors of 10, which add zeros to the product.
40x50=200
you have to remember, the factors of 10 that add zero the product. ex. 50 x 80 = 4,000
I dont get this because i have this on my homework but my teacher said that there was an answer
Riley's mom is correct, the strategy of counting zeros in the factors and putting them in the product does not always work for multiplying whole numbers by multiples of 10. The reason is that not all numbers are simply composed of a certain number of zeros.
To understand why this strategy does not work in every case, let's consider the example Riley's mom asked for: 7,000 multiplied by 600. According to Riley's strategy, since there are three zeros in 7,000 and two zeros in 600, the product should have a total of five zeros. However, the actual answer is 4,200,000, which has six zeros.
To correctly calculate the multiplication, we need to understand that multiplying a whole number by a multiple of 10 is essentially the same as shifting the digits of the number to the left. In this case, multiplying 7,000 by 600 can be broken down into two steps:
Step 1: Multiply 7,000 by 6.
This is a standard multiplication, resulting in 42,000.
Step 2: Shift the digits of 42,000 one place to the left.
Shifting the digits of a number one place to the left means adding a single zero at the end of the number. Thus, the product of 42,000 shifted one place to the left is 420,000.
Therefore, the correct answer for 7,000 multiplied by 600 is 420,000, not 4,200,000. This demonstrates why just counting zeros in the factors doesn't always give us the correct product.