## Add and Subtract within 1000

#### Aligned To Common Core Standard:

**Grade 3 Base Ten** - 3.NBT.2

**Tips for Subtracting Three-Digit Numbers** - Subtraction is one of the most basic operations in mathematics. When you are subtracting two numbers, it means that a specific value is being reduced from another value. Let 's learn how we can subtract one three-digit number from another three-digit number.
Suppose you have a number 236, and you have to take away or reduce 123 from it. So mathematically, you represent this problem by putting them vertically. First, write the number which is being reduced, and below will be the value dictating how much to be reduced. Like this,
236 - 123 = ? Remember, you always start subtraction from right to left, i.e. we start by deducting 3 from 6. Like this,
236 - 123 = 113
Let 's take another problem slightly more complex. How will you subtract 249 from 675? Remember, you can 't deduct a bigger number like nine from a smaller number like 5.
In this case, you will borrow or carry 1 from the number on the immediate left of the first number which is 7. It will make 7 into 6, and the 5 will become 15. 15 minus 9 is 6, and the remaining process will be the same.
675
-249
= 426

### Printable Worksheets And Lessons

- Mixed Step-by-step
Lesson- Start with an expanded form problem, then move on to
a sum and a difference.

- Guided Lesson
- These are pretty random. I was just trying to cover everything
in a sort of shotgun approach, I guess.

- Guided Lesson Explanation
- This one is a complete walk through for each problem.

- Practice Worksheet
- We add and subtract vertically and then we ask kids to setup the
problems themselves based on input / output chart.

- Matching Worksheet
- Find the missing part of each problem.

#### Homework Sheets

One homework on each skill and the third sheet mixes them together.

#### Practice Worksheets

A direction based sheet, some matching, and some honest problems for you.

- Practice 1- Add and subtract the number at the top of the table to each of the numbers in the left column.
- Practice 2
- Practice 3
- Practice 4 - Find the letter of the answer that matches the problem.