Final answer:
To round each mixed number to the nearest whole number, round down if the fraction part is less than 1/2 and round up if it is 1/2 or greater. The estimated product of 3 4/5 x 5 1/8 is 20.
Step-by-step explanation:
To round each mixed number to the nearest whole number, we need to look at the fraction part of the number. If the fraction part is less than 1/2, we round down, and if the fraction part is 1/2 or greater, we round up. Therefore, 3 4/5 rounds to 4 and 5 1/8 rounds to 5.
Now, to estimate the product, we multiply the rounded whole numbers: 4 x 5 = 20. So, the estimated product is 20.
Learn more about Rounding mixed numbers and estimating multiplication