# Question Video: Subtracting Two-Digit Numbers from Three-Digit Numbers Using a Place Value Table Mathematics • 2nd Grade

Subtract 2 tens and 3 ones from 437. Hint: Use the place value blocks if you need to.

03:37

### Video Transcript

Subtract two 10s and three ones from 437. Hint: Use the place value blocks if you need to.

In this question, we need to subtract or take away a number from 437. And it’s interesting because the number that we need to take away isn’t written as a numeral; we’re told it in terms of the number of tens and ones that make it up. We’re told to take away two 10s and three ones. Now we know that a number that has two 10s is going to be twenty something. And if it has three ones, it’s the number 23. And to help us solve the problem, we can think about the number 437 like this. In other words, we can think of its place value. It has four 100s, three 10s, and seven ones. And can you see that the way that we’ve written these numbers on top of each other like this, it shows the hundreds, the tens, and the ones really clearly in separate columns?

That’s why if we write a subtraction like this, we call it column subtraction. And it’s a method we can use to find the answer really quickly. Perhaps, you notice over here we’ve already got our column subtraction written out for us. So let’s use this method to help us find the answer. And we’re given a hint to use the place value blocks if we need to. So what we’ll do as we’re working out the answer using column subtraction, we’ll take away some of the place value blocks. And we’ll sort of mirror what we’re doing in the column subtraction with the place value blocks; it’ll help us understand it.

Now we always start with the smallest value place when we’re doing column subtraction. So we’re going to start with the ones. And we’re told that we need to take away three ones. And we know that 437 has seven ones, so we’re beginning with seven ones, and we’re taking away three of those ones. This is where perhaps we could use our place value blocks to show what goes on. We’re gonna take away one, two, three. Can you see how many we’re left with? Seven ones take away three ones leaves us with four ones. So we know whatever answer we’re going to get at the end of this, it’s going to have four ones.

Next, we move on to the tens. And we need to take away two 10s. And we can see that 437 has three 10s. If we look across at our place value blocks, we can see there’s three 10s. So let’s subtract two of them: one, two. Of course, three 10s take away two 10s is only going to leave us with one 10. So now we can see our answer is going to have one 10 and four ones. It’s going to be something and fourteen.

Now if we look at our column subtraction, we can’t see any hundreds we need to take away. We were only asked to subtract a number of tens and ones, weren’t we? So we started off with four 100s and we’re going to end with four 100s too. And you should be able to see that this three-digit number that we have as our answer is exactly the same as the number of place value blocks that we have left over. There are four 100s, one 10, and four ones. We’ve used column subtraction to take away two 10s and three ones from 437. And we found that 437 subtract 23 equals 414.