Beyond Rankers Academy
Building Minds, Not Just Rankers
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Beyond Rankers Academy
Building Minds, Not Just Rankers
Main site →
A decimal point splits a number into wholes and parts smaller than one. Line up the points, and adding or subtracting decimals is just as easy as whole numbers.
After the decimal point come tenths, then hundredths, then thousandths — each place is 10 times smaller.
4.725 broken into places
| Ones | . | Tenths | Hundredths | Thousandths |
|---|---|---|---|---|
| 4 | . | 7 | 2 | 5 |
4.725 = 4 + 7/10 + 2/100 + 5/1000
Compare digit by digit, starting right after the decimal point — never by how many digits there are.
Trap: 0.5 is bigger than 0.45, even though "45" looks like the bigger number. Compare the tenths digit first: 5 tenths beats 4 tenths.
Line up the decimal points directly under each other, then add or subtract as usual.
12 IMO-style questions on place value, comparing and calculating with decimals. 🍀