Two ways of counting the day

An original literary non-fiction-style account of watching relatives check the takings in a small shop.

At closing time, my uncle placed an abacus on the counter beside a calculator. He had used the frame for years. My cousin preferred the calculator and usually brought a pen as well. Between them lay receipts held under a stone paperweight, their curled edges still trying to rise.

My uncle moved the beads with quick, small gestures. The frame made a dry clicking sound against the counter. My cousin entered figures from a separate list, pausing to tick each line. Neither watched the other’s hands. I expected them to finish with the same total and a brief argument about which method had been quicker.

They did not get the same total. My uncle looked at the receipts, and my cousin looked at the calculator’s display. For a moment, each seemed to regard the other’s object as the likely source of the difference. Then my aunt came from the storeroom and asked which list they had used. One included a sale made just before closing. The other did not.

The two devices had answered two slightly different questions. My cousin added the missing amount, checked the line beside it and passed the list across. My uncle began again more slowly, then nodded. He asked for the pen to note a return which would have to be dealt with the next day. My cousin moved the abacus to make room for another sheet without making a comment about its age.

As they put the shop away, the calculator went into a drawer and the abacus returned to a shelf beside the till. The paperweight remained on the counter, holding down the corrected list. Outside, a customer tried the locked door and raised a parcel towards the glass. My aunt pointed to the opening times, then came back to the list and wrote one more reminder before turning out the light.

What do you learn from the whole passage about how the relatives achieve an agreed record of the day?