Decimals to Thousandths and Decimal Operations

Decimals to thousandths complete the decimal place value system students will use throughout secondary school. 0.375 is 3 tenths, 7 hundredths, 5 thousandths — or 375 out of 1000 equal parts of a whole. Thousandths appear in athletic timing (10.004 seconds), precise measurements (1.250 kg), and unit pricing ($2.375 per litre). Adding and subtracting decimals requires only one rule beyond whole-number arithmetic: align the decimal points so that tenths add to tenths, hundredths to hundredths, thousandths to thousandths.