Historical clue formulations

• Kindergarten math lesson — 2020-05-08
• Contributing (to) — 2017-11-07
• Doing sums — 2016-03-29
• Summer job? — 2016-02-06
• Totaling — 2006-10-16
• Simple arithmetic — 2006-01-22
• Summing — 2004-05-25
• Calculator job — 2001-08-04
• Totaling — 1998-10-26