Mario estimated the product of 132.4 × 27.9 in two different ways, as shown below.

To find the exact product of 132.4 and 27.9, we can multiply the two numbers together:

\[ 132.4 \times 27.9 = 3696.96 \]

Now, let's analyze Mario's estimates:

1. Using compatible numbers:

   • Mario estimated \( 132.4 \times 27.9 \) as \( 130 \times 30 = 3900 \).
   • This estimate is higher than the exact product of 3696.96.

2. Rounding to the nearest whole number:

   • Mario rounded \( 132.4 \) to \( 132 \) and \( 27.9 \) to \( 28 \) and calculated \( 132 \times 28 = 3696 \).
   • This estimate is very close to the exact product, with only 0.96 difference.

Conclusion about Mario's estimates:

• His first estimate using compatible numbers (3900) was higher than the exact product.
• His second estimate, when rounding to the nearest whole number (3696), was very close, just slightly less than the exact product at 3696.96.

Summary of observations:

• One estimate (compatible numbers) was significantly higher than the exact product.
• The other estimate (rounding) was very close to the exact product.
• Mario's estimates demonstrated that while compatible numbers can lead to larger discrepancies, rounding can provide a more accurate estimate.