Add and subtract multi-digit whole numbers including using a standard algorithm with procedural fluency.

Recall addition facts with sums to 20 and related subtraction facts with automaticity.

Identify the number that is ten more, ten less, one hundred more and one hundred less than a given three-digit number.

Compose and decompose three-digit numbers in multiple ways using hundreds, tens and ones. Demonstrate each composition or decomposition with objects, drawings and expressions or equations.

1. 8 ones can't be subtracted from 2 ones, so you will need to regroup 7 tens into 6 tens plus 10 ones.
2. Add the 10 ones to the 2 ones to make 12 ones. Subtract 8 ones from 12 ones to get 4 ones.



3. 8 tens can't be subtraced from 6 tens, so you will need to regroup 6 hundreds into 5 hundreds plus 10 tens.
4. Add the 10 tens to the 6 tens to make 16 tens. Subtract 8 tens from 16 tens to get 8 tens.



5. Subtract 3 hundreds from 5 hundreds to get 2 hundreds.
6. Final answer: 284

Start with 672, modeled with base 10 blocks.

We start by subtracting the ones. We can’t subtract 8 ones when there are only 2 ones.

We must regroup one of the tens into 10 ones.

We regroup 1 ten into 10 ones.

Now, we have 12 ones. We can subtract 8 ones.

There are 4 ones left.

Next, we will subtract the tens. We can’t subtract 8 tens from only 6 tens, so we will need to regroup one hundred.

Now, there are 16 tens. We can subtract 8 tens.

There are 8 tens left.

Now, we subtract 3 hundreds from 5 hundreds.

Final answer: 284

Click here for an animation of how place value blocks can be used to help students understand subtraction. Note: This animation may not be the right size to be clearly seen on a phone. The image changes approximately every 10 seconds.