🔢 Place Value with Decimals (Thousandths)

What is a Decimal?
A decimal is a way to show numbers less than 1 using a decimal point (•). The decimal point separates whole numbers from parts of a whole.
Place Value Chart:
HundredsTensOnes•TenthsHundredthsThousandths100101•1/101/1001/1000003•425Reading Decimals:
• 0.425 = "four hundred twenty-five thousandths"
• 3.7 = "three and seven tenths"
• 5.082 = "five and eighty-two thousandths"

Writing Decimals:
• "Six and fifteen hundredths" = 6.15
• "Two hundred thirty-four thousandths" = 0.234

What is Rounding?
Rounding makes numbers easier to work with by finding the closest "nice" number.
Steps to Round Decimals:
• Find the place value you're rounding to (tenths, hundredths)
• Look at the digit to the right
• If it's 5 or more → round UP
• If it's 4 or less → round DOWN (stay same)

Rounding to Tenths:
• 3.47 → Look at hundredths place (7 ≥ 5) → round up → 3.5
• 3.42 → Look at hundredths place (2 ≤ 4) → round down → 3.4

Rounding to Hundredths:
• 5.673 → Look at thousandths place (3 ≤ 4) → round down → 5.67
• 5.678 → Look at thousandths place (8 ≥ 5) → round up → 5.68

How to Compare Decimals:
Method 1: Use Place Value
• Compare whole numbers first
• If whole numbers are equal, compare tenths
• If tenths are equal, compare hundredths
• Continue to thousandths if needed

Method 2: Use Common Denominator
• 0.8 = 8/10 = 80/100
• 0.79 = 79/100
• 80/100 > 79/100, so 0.8 > 0.79

Method 3: Use Number Line
• Numbers to the right are greater