Decimals: Size, Order & Powers

Decimals: Size, Order & Powers

Understanding place value Comparing decimal sizes Working with powers of 10

What Are Decimals?

Parts of a whole number Use a decimal point to separate whole and fractional parts Each position has a specific place value Help us express precise measurements

Decimal Place Value Chart

Place Value Practice

Look at the number 45.237 What digit is in the tenths place? What digit is in the hundredths place? What is the value of the 2?

Reading Decimal Values

0.1 = one tenth 0.01 = one hundredth 0.001 = one thousandth Each place is 10 times smaller than the one before it

Comparing Decimal Sizes

{"left":"Start from the left\nCompare digits in the same place value\n0.5 > 0.05","right":"0.23 < 0.3\nAdding zeros doesn't change value: 0.5 = 0.50\nLine up decimal points when comparing"}

Quick Check: Order These Decimals

Which is largest? 0.8, 0.08, 0.008, 0.80 Discuss your reasoning with a partner

Powers of 10 with Decimals

Multiplying by 10: move decimal point right Dividing by 10: move decimal point left Each move changes place value by factor of 10 Pattern works for 100, 1000, etc.

Powers of 10 Practice

Start with 3.45 × 10 = ? × 100 = ? ÷ 10 = ? ÷ 100 = ?

Key Takeaways

Decimals help us express parts of wholes precisely Place value determines the size of each digit Comparing decimals: align decimal points and compare left to right Powers of 10 move the decimal point predictably