Estimation Flashcards

The process of finding an approximate value that is close to the exact answer.

Adjusting a number to the closest multiple of 10. For example, 47 rounds to 50.

Adjusting a number to the closest multiple of 100. For example, 364 rounds to 400.

Rounding a number to a specified number of significant digits. For example, 0.004567 to 2 significant figures is 0.0046.

Rounding a number to a specified number of decimal places. For example, 3.14159 to 2 decimal places is 3.14.

Cutting off a number after a certain decimal place without rounding. For example, truncating 3.456 to 2 decimal places gives 3.45.

Round each number to a suitable degree of accuracy and then add. For example, 47 + 364 ≈ 50 + 400 = 450.

Round each number to 1 significant figure and then multiply. For example, 47 × 364 ≈ 50 × 400 = 20,000.

Round each number to 1 significant figure and then divide. For example, 364 ÷ 47 ≈ 400 ÷ 50 = 8.

Use estimation to verify if a calculated answer is reasonable by comparing it to an approximate value.