Question

Ridley told his mom that multiplying whole numbers by multiples of 10 was easy because you just count the zeros in the factors and put them in the product. He used these two examples to explain his strategy: 7000 × 600 equals 4,200,000. Ridley's mom said his strategy will not work. Why not? Give an example to illustrate.

Answer 1

Ridley's strategy of counting zeros in multiplication of whole numbers by multiples of 10 does not always work. An example is provided to illustrate this.

Step-by-step explanation:

Ridley's strategy of counting the zeros in the factors and putting them in the product is not always correct when multiplying whole numbers by multiples of 10. This strategy only works when there are no numbers in front of the zeros. For example, 7000 multiplied by 600 equals 4,200,000 using this strategy. However, if there are numbers in front of the zeros, like in 10,000, the strategy does not work because the zeros represent an increase in place value. So, multiplying 10,000 by 600 would not give the correct answer of 6,000,000.