Multiple Digit Addition Made Easy!
Multiple digit addition is the last step in my whole number section. Before continuing be sure your child is comfortable with the following.
Number Comprehension
Addition Concepts
Transition to Number Line
Single Digit Addition
Use Base 10 Blocks to teach Double Digit Addition
Base 10 Blocks are a wonderful tool to teach your child multiple digit addition where 'carry over' exists. If you are not familiar with this manipulative, or just don't own them, you can
go here
to learn about them, and to access a free printable template to create your own.
The only rule of Base 10 Blocks
You can NEVER have 10 or more of any one type of block. If I do, I must trade 10 of the smaller block for 1 of the next size up.
That's it! Your child must know this and understand it, and the following information should make this clear to you. Once your child gets the hang of this - multiple digit addition will never be a problem again!
Worked Example - Addition problem 9 + 13 = ?
To proceed with this example you will need my
Multiple Digit Addition Template.
Step 1.
Just as with the grouping method of addition, count out 9 squares and place them in the units box on Line 1 of the addition template.
Step 2.
Count out 13 Squares and place them in the units box on Line 2 of the template.
Step 3. Ask the question!
Do you have ten or more of any type of block in any box?
Answer - YES. (There are 13 squares in Line 2)
Ask the question!
What is the rule?
Your child should know the rule from above!
Step 4. Trade up!
Count out 10 Squares and 'trade up' to 1 long.
Step 5. Put all block types in the correct positions.
Put the long in the 10's box of line 2.
Step 6. Combine Units into line 3.
Step 7. Ask the question!
Do you have ten or more of any type of block in any box?
Answer - YES. (There are 12 squares in the units box of Line 3)
Ask the question!
What is the rule?
Step 8. Trade up!
Count out 10 Squares and 'trade up' to 1 long. Put this long in the 10's box on line 3.
Step 9. Combine all longs from lines 1 and 2, into line 3.
Step 10. Read the answer.
There are 2 longs in the 10's box of line 3, and 2 squares in the units box of line 3, giving us the answer 22.
9 + 13 = 22
And that is it. The trade up, is what traditionally was called 'carry over'. This may seem like a long winded way to explain addition, however I can almost guarantee that once your child is adding this way, no addition problem will give them trouble ever again.
Ensure your child gets a lot of practice with this method, and it will soon become second nature. Print off my
Multiple Digit Addition Worksheets
which correspond with the addition template, and watch, as your child becomes an adding machine!
As they say, a picture (or video in this case) is worth a thousand words. To see just how easy using these blocks actually is visit
this YouTube video
to see a worked example.
Explore the entire
printable math worksheets
site, for more great elementary math problem solving techniques.
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