Final answer:
To find the product of 0.4, 3.29, and 25 using mental math, first, multiply 0.4 by 25 to get 10, and then multiply 10 by 3.29 to obtain the final product of 32.9.
Step-by-step explanation:
To solve the product 0.4× 3.29× 25 using mental math, we can rearrange and regroup the numbers for easier multiplication. First, notice that 25 is easily multiplied by 4 (as 25 is a quarter of 100 and 4 is 1/10th of 40). Now multiply 0.4 by 25 to get 10 because 0.4 is the same as 2/5 and 25 times 2 equals 50 divided by 5 equals 10. Then, multiply the result by 3.29 to find the final product. This way, we simplify the mental math process by handling smaller, more manageable numbers first, and doing the more complex multiplication only at the end.
The product of 0.4 and 25 is 10, and then multiplying 10 by 3.29 gives us 32.9.