Answer:
I agree with Carmen's approach. Doubling 4×9 is equivalent to multiplying 8×9, which both give a product of 72.
Explanation:
When Carmen says she doubles 4×9, she means she is taking the result of 4×9, which is 36, and then multiplying it by 2. So, doubling 4×9 gives us 72, which is the same as the product of 8×9. Therefore, I agree with Carmen's approach.