Subtracting gets hard when the numbers stop feeling concrete. If you can see the tens and ones in front of you, the problem usually makes more sense.
That is why base 10 blocks help so much. They let you watch subtraction happen, piece by piece, and they make regrouping easier to understand.
If you are working with a 2nd or 3rd grader, or teaching one, the video below gives you the visual model first. Then the written guide walks you through the same process in clear steps.
What base 10 blocks show you in subtraction
Base 10 blocks are classroom manipulatives that help you see place value. Instead of treating a number as a string of digits, you can build it with pieces. That matters in subtraction because you are taking parts away, and you need to know which parts are ones, which are tens, and which are hundreds.
These are the three block types used in the lesson:
Block type | Value | What it looks like when you draw it
Ones cubes | 1 | A dot or small square
Tens rods | 10 | A line or long rectangle
Hundreds flats | 100 | A large square
When you subtract with these blocks, you start by building the top number. Then you remove the amount in the bottom number. In other words, subtraction is a take away action, and the blocks let you see that action instead of only memorizing a rule.
This approach also works when you do not have the physical blocks. You can draw the same place-value model on paper. That is one of the most useful parts of this method. A child can begin with manipulatives in class, then move to pencil-and-paper drawings at home without changing the underlying idea.
That connection matters because regrouping often feels mysterious when it first appears in written subtraction. With blocks, it is not mysterious at all. You can see one ten turn into ten ones. You can count them. You can subtract from them. Then you can connect that action to what happens in the written algorithm.
If you have already used base 10 blocks for addition, subtraction will feel familiar. You still build the number by place value. The difference is that now you remove blocks instead of combining them.
Solving 95 – 13 without regrouping
Start with a subtraction problem that does not need regrouping: 95 – 13. This is a good first example because you can focus on place value and the meaning of subtraction before dealing with trades between places.
To build 95, you need 9 tens and 5 ones. If you are using blocks, place nine tens rods in front of you, then add five ones cubes. If you are drawing it, sketch nine long lines for the tens and five dots for the ones.
Then subtract 13 in order from the smallest place value to the larger one.
- Remove 3 ones from the 5 ones.
- Remove 1 ten from the 9 tens.
- Count what is left.
After you take away the 3 ones, you still have 2 ones. After you take away 1 ten, you still have 8 tens. That leaves you with 82.
What you should notice in the ones place
The ones place is simple here because you have enough ones to subtract. You start with 5 ones, and the problem asks you to take away 3. Since 5 is greater than 3, you do not need to regroup.
That is an important idea for children to hear early. Not every subtraction problem needs borrowing or regrouping. First, you check the ones place. If you have enough ones, you subtract them and move on.
With blocks, that step is easy to see. You physically remove three cubes, place them aside, and then count the cubes that remain. On paper, you cross out three of the drawn ones and count what is left. The meaning stays the same in both versions.
How to draw 95 – 13 on paper
If you do not have manipulatives nearby, you can solve the same problem with a sketch.
Draw nine tens and five ones. Then cross off three ones and one ten. Now count what remains. You should see two ones and eight tens, which is 82.
This paper version matters because it helps you bridge concrete work and written math. A child who can draw the tens and ones is less likely to treat subtraction as a random procedure. The drawing keeps the place values visible.
That is often the missing piece when a child can recite steps but cannot explain why the answer is correct. The blocks and the drawing both answer that question. They show you what was there first, what got taken away, and what remained.
Solving 242 – 35 with regrouping
Now move to a problem that does need regrouping: 242 – 35. This is where base 10 blocks become especially helpful, because the written shortcut can feel strange until you see the trade happen.
To build 242, place 2 hundreds flats, 4 tens rods, and 2 ones cubes in front of you. If you are drawing instead, sketch two large hundred squares, four tens lines, and two ones dots.
You always begin with the smallest place value, so start with the ones place. The problem asks you to subtract 5 ones. However, you only have 2 ones. You cannot remove 5 ones from a set of 2 ones, so you need to regroup.
What regrouping looks like with blocks
Take away 1 ten rod from the tens place. That rod has a value of 10, so you exchange it for 10 ones. Then place those 10 new ones in the ones place with the 2 ones you already had.
Now your ones place has 12 ones, and your tens place has only 3 tens left.
When you regroup, you add 10 more ones to the ones place. You do not stop when the total reaches 10.
This is a common mistake for children. If a child starts with 2 ones, that child may try to add only 8 more so the total becomes 10. That is not what the trade means. A ten rod is always worth 10 ones, so you must add all 10 new ones. Since you already had 2 ones, the new total is 12 ones.
Once you have 12 ones, subtract the 5 ones from the problem. After you remove 5 ones, you have 7 ones left.
Finish the tens and hundreds places
Now return to the tens place. Before regrouping, you had 4 tens. After you traded 1 ten for 10 ones, you now have 3 tens. The subtraction problem asks you to remove 3 tens, so you take away all 3. That leaves 0 tens.
Then look at the hundreds place. The problem does not ask you to subtract any hundreds, so the 2 hundreds stay where they are.
When you combine the remaining place values, you get:
- 2 hundreds
- 0 tens
- 7 ones
So the answer is 207.
This is one of the best reasons to use base 10 blocks. The answer does not appear by magic. You can watch the 1 ten leave the tens place, reappear as 10 ones, and then help you subtract the ones correctly.
How the written regrouping matches the visual model
On paper, you show the same action in a faster form. You begin with 242. Then you regroup one ten into the ones place, which changes the 4 tens to 3 tens and the 2 ones to 12 ones.
After that, the subtraction becomes easier to read:
- 12 ones minus 5 ones leaves 7 ones.
- 3 tens minus 3 tens leaves 0 tens.
- 2 hundreds stay the same.
The key is that the written marks only make sense if you understand the trade behind them. The blocks make that trade visible. The drawing keeps the same logic on the page.
Why base 10 blocks make subtraction easier to learn
Children often struggle with regrouping because the written method compresses several ideas into a few pencil marks. A small number is crossed out, a new number is written above it, and the child is expected to know what changed. Base 10 blocks slow that down. They let you see each change in place value.
That makes subtraction less about memorizing a rule and more about understanding quantity. You are not “borrowing” in a vague way. You are exchanging one ten for ten ones. You can count them. You can touch them. You can remove them one by one.
For 2nd and 3rd graders, that visual step is often the bridge between early place-value work and more formal written subtraction. The method is also useful for parents and teachers because it gives you language to explain what is happening. You can say, “You did not have enough ones, so you traded one ten for ten ones,” and the child can see that sentence happen with the blocks.
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The main idea to keep with you
Subtraction becomes easier when you can see place value. In 95 – 13, you remove ones and tens without regrouping. In 242 – 35, you regroup because the ones place does not have enough to subtract 5.
That is the heart of the method. You begin in the ones place, trade when needed, and then count what remains in each place.
Once you understand that exchange, the written subtraction steps stop feeling random. You are no longer guessing what the crossed-out numbers mean, because you know the blocks behind them.
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