In abacus math lesson 3 we are ready to look at combining numbers by adding and subtracting numbers within a single rod on the abacus or soroban. If you are not sure about how to enter or remove any of the digits 1 through 9 on the abacus, please take a look at abacus math lesson 1 for counting 0 to 5 and abacus math lesson 2 for counting 6 through 9. None of these examples will require the use of complements, i.e. the need to borrow from or carry to the next adjacent rod, and therefore will be straightforward. All operations can be worked out on a single rod. However, pay close attention to the actual bead movements and associated fingering to ensure consistent practice to gain speed and accuracy.