Number & Operations in Base Ten

Reading & Comparing Decimals

Reading, writing, and comparing decimals to the thousandths place.

Intermediate15 min lesson3 min readUpdated August 12, 2026Author not yet attributed

Prerequisites

Powers of Ten

Decimal Place Value to the Thousandths

Which is larger: 0.4 or 0.25? Before reading on, make a guess — and notice if any part of you was tempted to say 0.25 is bigger because '25 is more than 4.'

0.4 is actually larger. The digits after a decimal point aren't compared like a whole number — each one has its own separate place value: tenths, then hundredths, then thousandths, each place worth exactly one-tenth of the place before it. 0.4 means 4 tenths, which is the same as 0.40, or 40 hundredths — more than 0.25's 25 hundredths.

To compare two decimals, line up their decimal points and compare digit by digit from left to right, exactly the way whole numbers are compared — tenths first, then hundredths, then thousandths, stopping as soon as a difference appears.

Worked Example — Comparing Decimals to the Thousandths

Compare 0.362 and 0.36. Rewrite 0.36 as 0.360 so both numbers show three decimal places. Comparing digit by digit: tenths (3 = 3), hundredths (6 = 6), thousandths (2 versus 0). Since 2 is more than 0, 0.362 is larger: 0.36 < 0.362.

Worked Example — Reading a Decimal to the Thousandths

Read 0.508 aloud. The digits after the decimal point represent 5 tenths, 0 hundredths, and 8 thousandths — read together as the fraction they represent: five hundred eight thousandths.

Tip

Writing trailing zeros onto a shorter decimal, like turning 0.36 into 0.360, doesn't change its value at all — it just makes lining up the digits for comparison easier.

Common Mistakes

Comparing decimals as if more digits after the point always means a larger number, treating 0.25 as bigger than 0.4 by comparing '25' to '4' as whole numbers.
Compare place value by place value, starting from the tenths digit, not the total number of digits — 0.4 has 4 tenths, more than 0.25's 2 tenths, so 0.4 is larger regardless of how many digits follow.
Skipping a place value entirely when a digit is 0, and shifting the remaining digits to fill the gap.
Every place value must be accounted for, including zeros — 0.508 has 0 hundredths exactly where it's written, and that 0 can't be skipped when reading or comparing the number.

Key Takeaways

Decimal place value continues past hundredths into thousandths, with each place worth one-tenth of the place before it.
Comparing decimals means comparing digit by digit from the tenths place onward, not comparing digit counts.
Adding trailing zeros to a decimal doesn't change its value, and can make comparison easier.

Summary

Extending place value to the thousandths gives decimals the same precise comparison as whole numbers. With reading and comparing settled, the next lesson puts decimals to work in addition and subtraction.

Track your progress

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