Add Whole Numbers

We can use models to add numbers with regrouping

Steps to add two numbers:
Step 1: Add ones and regroup if necessary
Step 2: Add tens and regroup if necessary
Step 3: Add hundreds and find the sum

10 ones = 1 tens, 10 tens = 1 hundreds

Steps to add dollar amounts:
Step 1: Add ones and regroup if necessary
Step 2: Add tens and regroup if necessary
Step 3: Add hundreds and find the sum

To add dollars and change, add as you would whole numbers. After addition, write the dollar sign and place the decimal point in the sum

Remember to place the decimal point in the sum in line with the decimals points of the numbers being added

There are different methods we can use to add. One of these is called the partial-sums method

For example, add 245 and 187 using partial-sums method. Steps to follow:

Step 1: Add the 100s
200 + 100 = 300

Step 2: Add the 10s
40 + 80 = 120

Step 3: Add the 1s
6 + 7 = 12

Step 4: Add the sums we just found (the partial sums)
300 + 120 + 12 = 432

Steps to follow to add two numbers using column-addition method:

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