Montessori Casa International, Denver, Children Sing On the 31st January 2020, the children of the Montessori Casa International, in Denver Colorado, celebrated Maria Montessori's 150th Birthday. Tags Song United States Denver Montessori Social Elementary School Splot, Poland Sing Video: Geneva Admin Course Sings Nienhuis Tulip Puzzle Promotional Video Kate Oliver Singing My Hand in Your Hand China Conference Premieres Montessori 150 Song