Place Value and Number Sense
Place value is the idea that a digit's value depends on its position in a number. In Year 3 (ACARA v9), students work with numbers beyond 10 000, learning that in 4275 the 4 means 4 thousands, the 2 means 2 hundreds, the 7 means 7 tens and the 5 means 5 ones. The key idea: the same digit is worth different amounts in different places — the 2 in 2000 is worth ten times the 2 in 200. Understanding place value lets children read, write, compare and order large numbers, and it is the foundation for adding, subtracting and regrouping.
Worked examples
What is the value of the 7 in 3785?
Look at the position: the 7 is in the hundreds place, so it means 7 hundreds.
Answer: 700
Partition 4275 into place-value parts.
Split by position: 4 thousands, 2 hundreds, 7 tens, 5 ones.
Answer: 4000 + 200 + 70 + 5
Which is bigger: 5432 or 5423?
The thousands and hundreds match. Compare the tens: 3 tens versus 2 tens. 5432 has more tens.
Answer: 5432 is bigger
Real-world: a stadium holds 8640 people. What is the value of the 8?
The 8 is in the thousands place, so it means 8 thousands.
Answer: 8000
Tips
- •Name the place, then the value. In 3785 the 7 is 'in the hundreds', so its value is 700 — saying the place first stops mix-ups.
- •Line numbers up by place value to compare them. Compare from the left: thousands first, then hundreds, then tens, then ones, until the digits differ.
- •Common mistake to watch for: children often read 3785 as 'three, seven, eight, five' instead of 'three thousand seven hundred and eighty-five'. Reading the whole number aloud builds real number sense, not just digit-naming.
- •Use blocks or a place-value chart. Thousands, hundreds, tens and ones blocks make it clear why the 2 in 2000 is worth far more than the 2 in 20.