Grade 2 · Math · 2 minutes
Place value
Hundreds, tens and ones: where a digit sits tells you what it\'s worth.
Key terms
- place value
- How much a digit is worth, depending on where it sits in a number.
- ones
- The place on the right; each digit here is worth just that many single units.
- tens
- The middle place; ten ones snap together to make one ten.
- hundreds
- The place to the left of tens; ten tens make one hundred.
- expanded form
- Writing a number as the sum of what each digit is worth, like 300 plus 40 plus 5.
- zero as a placeholder
- A zero that holds a place so the other digits stay in the right spots.
Transcript
Hey there, number builders! Here are three digits. Three, four, and five. But how much is each one really worth? It all depends on its place!
This little cube is one. Let's line up ten ones. Now watch! Ten ones snap together to make one ten. Click!
Now let's stack up ten tens. Ten tens squish together to make one hundred! It's a big, flat square.
Let's build three hundred forty five. Three hundreds slide into the hundreds place. Four tens go in the tens place. And five ones go in the ones place.
Now look at the digit three. In the ones place, it's worth three. In the tens place, it's worth thirty. And in the hundreds place, it's worth three hundred! Same digit, different value.
We can stretch a number out to show what every digit is worth. Three hundred forty five is three hundred, plus forty, plus five. That's called expanded form!
What about three hundred five? There are no tens at all. So we write a zero in the tens place. The zero holds the place, so the five stays in the ones.
So remember! Ten ones make a ten. Ten tens make a hundred. And ten hundreds make one thousand! Where a digit sits tells you what it's worth.
Sources
Every fact in the video, and where it comes from.
- 1thecorestandards.org/Math/Content/2/NBT
- Grade 2 (CCSS 2.NBT.1): the three digits of a three-digit number represent amounts of hundreds, tens and ones; 100 can be thought of as a bundle of ten tens.
- Grade 2 (CCSS 2.NBT.2-3): count within 1000; read and write numbers to 1000 using base-ten numerals, number names and expanded form (e.g. 345 = 300 + 40 + 5).
- A zero shows an empty place: 305 has 3 hundreds, 0 tens and 5 ones; expanded form 300 + 0 + 5.
- 2schools.utah.gov/curr/mathematics/_mathematics_/_core/_math_cor…
- Base-ten blocks: a unit cube is 1, a rod is 10 cubes (1 ten), a flat is 10 rods (100), a large cube is 10 flats (1,000).
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