Math Help: Partial-Sums Addition and Column-Addition

Below are some tips that might be helpful when your student brings home their work on Tuesday. We are focusing on two different types of addition. They are:  Partial-Sums and Column-Addition.

I have written out an example, and I have also attached a link to a video that will help explain the process as well. It was difficult to format the example for Column-Addition, so I attached a photo. The steps are colored in coordination with the actual work in the photo. If you have questions, let me know! I know this is a very different method, than many of us, including myself, grew up with. We are in this journey together! I have found these methods fantastic for teaching addition, and really help students make sense of addition. Enjoy!


Partial-Sums

The partial-sums method is used to find sums mentally or with paper and pencil. Here is the partial-sums method for adding 2-digit or 3-digit numbers:

Steps:
1.) Add the 100s
2.) Add the 10s
3.) Add the 1s
4.) Then add the sums you just found (the partial sums).


Example:

                                                                          46
                                                                        +37 
Add the 10s:                    40+30 ----------->       70
Add the 1s:                        6+  7 ----------->     +13
Add the partial sums       70+13 ----------->       83

                                                                                   233
                                                                                 +158
Add the 100s:                  200+100 -------->                300
Add the 10s:                      30+  50 -------->                  80
Add the 1s:                         3 +   8 --------->                +11
Add the partial sums:  300 + 80 + 11 ----->                391



video link: http://www.youtube.com/watch?v=Vac6SUg9uSU


Column-Addition 

The column-addition method can be used to find sums with paper and pencil, but it is not a good method for finding sums mentally.

Here is the column-addition method for adding 2-digit or 3-digit numbers.

1.) Draw lines to separate the 1s, 10s, and 100s places.
2.) Add the numbers in each column. Write each sum in its column.
3.) If there are 2 digits in the 1s place, trade 10 ones for 1 ten.
4.) If there are 2 digits in the 10s places, trade 10 tens for 1 hundred.

Example:

Add 248+187 using the column-addition method.

Add the numbers in each column

Two digits in the ones place.

Trade 15 ones for 1 ten and 5 ones.

Move the 1 ten to the tens column.

Two digits in the tens place.

Trade 13 tens for 1 hundred and 3 tens

Move the 1 hundred to the hundreds column

248 + 187 = 435 

video link: http://www.youtube.com/watch?v=-B9oM-phD3g




I hope this information helped. If you every have more questions about our Everyday Math while you are at home, this is a really helpful site to view!This link will take you to the unit we are currently working on.
 http://everydaymath.uchicago.edu/parents/4th-grade/em-at-home/unit_2/