Understand the Purpose:

• Estimating products helps to quickly determine an approximate answer.
• It is useful for checking the reasonableness of a more precise calculation.

Identify Numbers to be Multiplied:

• Read the problem carefully and identify the numbers involved.
• Note any significant digits and place values.

Round the Numbers:

• Round each number to a value that makes multiplication easier.
• Common rounding options include the nearest ten, hundred, or thousand.
• Ensure rounding makes sense in the context of the problem.

Multiply the Rounded Numbers:

• Perform the multiplication with the simplified, rounded numbers.
• This gives a rough estimate of the product.

Adjust if Necessary:

• Depending on how much the numbers were rounded, you may need to adjust your estimate.
• Consider if the rounding caused the estimate to be too high or too low and make a mental note.

Check Reasonableness:

• Compare the estimate to the actual calculation if available.
• Ensure the estimate falls within a reasonable range of the exact product.

Example Problems

Problem 1: Estimate the product of 47 and 62.

Solution Steps:

Round the Numbers:

• 47 rounds to 50.
• 62 rounds to 60.

Multiply the Rounded Numbers:

• 50×60=3000

Final Estimate:

• The estimated product of 47 and 62 is approximately 3000.

Problem 2: Estimate the product of 345 and 89.

Solution Steps:

Round the Numbers:

• 345 rounds to 350.
• 89 rounds to 90.

Multiply the Rounded Numbers:

• 350×90=31500

Final Estimate:

• The estimated product of 345 and 89 is approximately 31500.

Problem 3: Estimate the product of 128 and 76.

Solution Steps:

Round the Numbers:

• 128 rounds to 130.
• 76 rounds to 80.

Multiply the Rounded Numbers:

• 130×80=10400

Final Estimate:

• The estimated product of 128 and 76 is approximately 10400.