The flags of the USA matching were designed to be part of a unit of study on the USA. In my Montessori classroom we do monthly themes on different continents and regions of the world. I made this flag matching to go with my unit of study on the USA.
When using this work I print two copies of the paper. One copy of the paper is the control sheet and the flags on the other copy are cut apart and matched to the correct flag on the control sheet.