Abacus logic

An abacus is a special tool that helps us do math. It's like a little calculator with beads that you can slide back and forth. You can use it to add, subtract, multiply and even divide!

Each row on the abacus represents a different place value. The first row has one bead, the second has ten beads, the third has one hundred beads, and so on. The beads that are moved up and down represent the numbers we are working with.

To add numbers on the abacus, we start by placing the first number on the left side of the abacus. Then, we slide beads to represent the second number. When we're done, we count the beads on each row to get our answer.

Subtracting on the abacus is similar to adding, but we move the beads in the opposite direction.

Multiplying on the abacus can be a little trickier. We use a technique called "multiplication by adding" where we add the same number over and over again, as many times as we need to, to get our answer.

Dividing on the abacus is also a bit more complicated, but we can use the same technique of "adding up" to find our answer.

Overall, using an abacus is a fun and visual way to do math. It's like playing with a toy while also learning important skills!