Place value chart with base ten blocks

How to use the place value chart

Trade 10 ones for 1 ten, or break a ten back into ones. The number appears in digits, in words and in expanded form, for any number from 0 to 999.

1. Choose Up to 99 for tens and ones, or Up to 999 to add hundreds.
2. Press + under a column to add a block, and − to take one away. A big flat is 100, a rod is 10 and a small unit is 1.
3. Watch the number change: in digits, in words and in expanded form, like 300 + 40 + 7.
4. Add ones until you have 10, then press Make a ten. The 10 ones trade for 1 rod. The number stays the same.
5. Press Break a ten to trade a rod back for 10 ones. This is what you do to take away from a number like 42 − 7.
6. Use the same buttons for hundreds and tens. Press Clear to start again.

What is a place value chart?

A place value chart is a table with a column for each place in a number: hundreds, tens and ones. A digit’s place tells what it is worth. In 347 the 3 means 3 hundreds, the 4 means 4 tens and the 7 means 7 ones.

Base ten blocks make this concrete. A unit is 1, a rod is 10 units and a flat is 10 rods, which is 100. Trading 10 of one block for 1 of the next is called regrouping, and it is the idea behind carrying and borrowing.

Ideas to try at home

• Ask your child to build their age, then the age of a parent, and read each number aloud.
• Build 24, then add 9 ones. Press Make a ten and read the new number.
• Build 40 and ask, "Take away 6." Press Break a ten first and see how many ones there are.
• Roll a die three times and build the number it makes in the three columns.
• Build 100 using only rods. How many rods is that?
• Say a number like 508 and ask what is in the tens column. There are 0 tens, which is why 508 needs its 0.

What it helps with

• Place value: knowing that a digit’s place tells what it is worth.
• Regrouping: trading 10 ones for a ten, and a ten for 10 ones, before adding and subtracting bigger numbers.
• Reading numbers: saying a number, writing it in digits and breaking it into expanded form.

Common Core standards that fit this tool, in the standards' own words:

• 1.NBT.B.2: Understand that the two digits of a two-digit number represent amounts of tens and ones.
• 2.NBT.A.1: Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones; e.g., 706 equals 7 hundreds, 0 tens, and 6 ones.
• 2.NBT.A.3: Read and write numbers to 1000 using base-ten numerals, number names, and expanded form.