Demonstrate how to represent 63.00 on the abacus. Place the abacus on a flat surface. Have the child count four columns from the right to be in the thousands place.
Write out the number on a blank sheet of paper where the number will land directly underneath the column it represents. Leave the ones and tens columns alone. Have the child move one heavenly bead down and one earthly bead up to represent six in the thousands place and move three earthly beads up in the hundreds column.
Show the child how to add. Have the child write 11.11 underneath 63.00 on the blank sheet of paper and add the two numbers to equal 74.11. Instruct the child to move one earth bead up in the thousands place and in the hundreds place to represent 7 and 4. Then move one heavenly bead down and one earthly bead up in the tens column to represent 11.
Show the child how to subtract. Have the child write 74.11 subtracted by 8.00 to equal 66.11. Have the child move one earthly bead down in the thousands place to represent 6 again. Tell the child to move one heavenly bead down and push one earthly bead up to represent 6 in the hundreds place.