How to Add Numbers Using Retrograde Methods

The term retrograde comes from the Latin word 'retrogradus', which literally means “backward step.” In English, the term means "reverse", "backwards", "reverting to". As the name suggests, retrograde addition means adding from backwards. Explore more below.

Step 1: Adding Column 1 From the Left

Column 1. Add vertically from the left. 2 + 1 + 2 = 5. Write 5 below the line as indicated. 

Step 2: Adding Column 2 From the Left

Add column 2. The numbers to add are 4 + 3 + 7 = 14. Write 4 below the line as indicated. Carry the tens of 14 i.e. 1 to the first column, and add it to 5 which is 6.  Write 6 below the 5 and cancel 5.

Step 3: Adding Column 3 From the Left

Add column 3. We have 7 + 5 + 5 = 17. Write 7 below the line as indicated. Carry the tens of 17 i.e. 1 to the second column, and add it to 4 which is 5.  Write the 5 below the 4 and cancel 4. 

Step 4: Adding Column 4 From the Left

Add column 4.The numbers to add are 5 + 4 + 7 = 16. Write 6 below the line as indicated. Carry the tens of 16 i.e. 1 to the third column, and add it to 7 which is 8. Write the 8 below the 7 and cancel 7. 

Step 5: Adding Column 5 From the Left

Add column 5. We have 3 + 7 + 3 = 13. Write 3 below the line as indicated. Carry the tens of 13 i.e. 1 to the fourth column, and add it to 6 which is 7.  Write the 7 below the 6 and cancel 6. From here, the numbers which are not cancelled form your sum 6 5 8 7 3.