Base ten blocks are in just about every elementary school building in the country. Because of how popular base ten blocks are, you’re probably familiar with what I’m talking about, but we’ll do a quick review just in case.

Base ten blocks are math manipulatives usually made of foam, plastic, or wood. They come in four sizes – units, rods, flats, cubes. Units are small 1 cm cubes. Rods are made up of ten connected units. The lines on flats show that they are made of 100 units or 10 rods. Finally, cubes are made up of 10 flats that form a 10x10x10 cube.

In the younger grades, base ten blocks are typically assigned the following values:

- Units = 1
- Rods = 10
- Flats = 100
- Cubes = 1000

However, it’s important not to name these blocks “ones,” “tens,” “hundreds,” and “thousands,” because in upper elementary, these blocks are often used to build a conceptual understanding of decimals, and will hold different values. When we name the blocks by value, students have the added hurdle of UNLEARNING those names later. That’s why we like to stick to units, rods, flats, and cubes.

Now, these blocks are super handy, especially when diving into addition and subtraction with large numbers. Let’s say students are beginning to add 123 and 379. Who wants to count out hundreds of individual objects to find the sum? Not me! Base ten blocks allow us to represent these larger numbers much more easily.

Now that we’re all on the same page, let’s chat about why some kiddos might not be *quite there* yet and how we can tell when students *are* ready to rock those blocks.

## Why Base Ten Blocks?

What makes base ten blocks so great? Base ten blocks come in uniform sizes with each block being ten times the size of the next smallest block (hello, base ten system!). With them, you can teach place value, addition, subtraction, multiplication, division, and even decimals. They make it easy to efficiently represent numbers, especially as numbers get bigger. On top of all of that, they are fairly inexpensive, especially if you go for the foam or plastic ones. What other manipulative is that versatile across topics and grade levels?

## Why Not Base Ten Blocks?

As awesome as base ten blocks are, they are not *always *the perfect fit. First, rods, flats, and cubes cannot be taken apart. The units that make them up are all stuck together. That can make it trickier for students to fully understand what composes a ten, hundred, or thousand.

Base ten blocks are also more abstract than using actual objects, photos of objects, or even connecting cubes. For students who are not ready to make the leap from literal objects to more abstract objects to represent problems, base ten blocks can be tricky. For example, if a student is adding 8 books and 3 books, using actual books is the best place to start. Using base ten blocks to represent books can be confusing for our youngest students.

Additionally, base ten blocks tend to come in sets of all the same color. For young students, not being able to see addends represented in different colors can be confusing.

Now that we know the pros and cons of base ten blocks, the big question is when do we bust them out for our students? Below I’ve got you covered with three signs that signal student readiness for this do-it-all manipulative.

## Sign #1: Students solidly understand the difference between 1 one and 1 ten.

Before students begin to use base ten blocks, they must have solidified the concept of unitizing. That is, they need to fully understand that in a multi-digit number, a digit will have different values based on its place because it represents groups of ones, tens, hundreds, etc.

Without unitizing, counting base ten blocks can feel like Mission Impossible! Students may count 1 unit and 1 rod as 2 rather than 11. Yikes! This misunderstanding would make it nearly impossible for them to use the manipulative successfully, especially when trying to add or subtract.

If your students aren’t there yet, no worries! Here are some activities to help them get there. You will not be surprised to find counting collections and number talks on there – two of my all-time favorites.

Once students have had sufficient practice with unitizing, here are some questions you can use to reflect on whether or not your students have solidified this concept:

- Can the student quickly recognize the teen number represented by a full ten frame and some additional ones?
- When counting groups of items, do they group items to make counting more efficient or do they count each individual item?

## Sign #2: Students can fluently count forward and backward by 10s or 100s from any number.

The second sign that students might be ready to use base ten blocks is that, in addition to being able to count on or back by 1s, they can skip count forward and backward by 10s or 100s starting at any number. When we skip count, our brains are mentally adding and subtracting, part of the foundation of adding and subtracting larger numbers.

When using base ten blocks, students need to be able to skip count to even just build numbers. For example, when building 53, students need to count by 10s to build 50: 10, 20, 30, 40, 50. Then they need to recognize that they need 3 more units to make 53.

When building numbers, sometimes students will already have some blocks in front of them and need to count on to build their target number. For example, if students already have 28 in front of them but need to build 53, they need to count on: first by 10s 38, 48, and then by 1s 49, 50, 51, 52, 53 without having to start over 0. This skill is a foundation for adding multiples of tens and hundreds to any number.

Two fairly quick, low- or no-prep questions you can ask your students to determine if they can skip count by 10s and 100s are below:

- Ask students to start at 40 and count on by 10s.
- Show students a small container and tell students that there are 24 cubes inside it. Then show them 3 ten-sticks of connecting cubes and ask them to figure out how many cubes there are in all. Some students may attempt to count them all or attempt the standard algorithm but really, we are looking for students to skip count: 34, 44, 54. If needed, you can ask them to skip count by 10s starting at 24.

## Sign #3: Students can explain and represent regrouping – and not just the algorithm!

Being able to explain regrouping is key! Well, *all *of these signs are key, but if students cannot explain what regrouping means, they are *definitely* not ready for base ten blocks.

Base ten blocks need to be “traded” to regroup. They are not physically connected and disconnected in order to regroup – they literally can’t be! Instead, students need to trade a rod for 10 units or vice versa.

Rather than beginning with base ten blocks that cannot be connected and disconnected, students need to physically connect 10 individual cubes to make a ten-stick and disconnect a ten-stick into 10 individual cubes. Not only that, they need to see and do that over and over and over before being asked to “trade” instead.

Trading base ten blocks does not accurately represent what is happening when regrouping. In fact, students often lose track of their work if they are not ready for that leap. I have often seen students lose track of their regrouping when using base ten blocks. What might this look like? Let’s take a peek.

Let’s say a student is working with the number 37 and needs to regroup to subtract 9. He took one of the three rods he had used to make 37 and began trading it for ones. However, when taking ones, he added the ones he took to the 7 he already had to make 10. Rather than taking out 10 ones and including those with the 7 ones he already had, he only took out 3 ones. Whoops! As a result, he ended up only having blocks to represent 30 instead of 37. Needless to say, he did not solve that subtraction problem correctly.

Instead, we want students to be able to clearly explain what is happening when they regroup. A student who can do this might say something like this:

“I have 37 and I can take one of the ten sticks and break it apart so it’s 10 cubes instead. I still have 37 but now I have 2 ten-sticks and 17 cubes. Now, I can take away 9 cubes. When I take away 9, I have 28 left. Two ten-sticks and eight extra ones.”

Notice that the student knows that when they regroup, the number of blocks they have has not changed. The way the number is represented may look different, but the value is the same. This understanding is critical and if your students have it, they may be ready for base ten blocks!

Let’s recap! Your students are ready to go with base ten blocks when they can: unitize, skip count, and explain regrouping. If you have kiddos who are there – have at it! Base ten blocks are truly an amazing manipulative that can help grow students’ math understanding.

But… what to do if they aren’t ready? Give Unifix cubes a try! I have an entire post where I detail why I love them for students who are not yet ready for base ten blocks. Either way, happy mathing!

## Leave a Comment