About Theodor Haagaas
Lived 1873 – 1961 (aged 88). Theodor Haagaas was a Norwegian mathematician.
Theodor Christian Petersen Haagaas (15 June 1873, Tistedalen – 25 December 1961, Oslo) was a Norwegian mathematician, mathematics educator and private school owner.
He was the founder and owner of the Haagaas School, a private gymnasium at Frogner, Oslo that existed 1915–1955. Haagaas School was Norway's best known intensive gymnasium or "student factory" in the first half of the 20th century, in the tradition of the historical Heltberg School of the 19th century; the noted educator Mosse Jørgensen wrote that "if any school had deserved the epithet 'The New Heltberg', it was Haagaas School."
In 1908 he married his former pupil Henriette Wegner Paus (1879–1942), a university-educated teacher at Nissen's Girls' School. She was the daughter of Bernhard Pauss and Henriette Pauss (née Wegner), major figures in the development of girls' education in Norway and long-time owners and leaders of Nissen's Girls' School, and the granddaughter of the mining magnate Benjamin Wegner and the banking heir and philanthropist Henriette Wegner. His wife was a goddaughter of Wilhelm Adelsten Maribo. Theodor and Henriette were the parents of four daughters, among them the journalist, humanist and resistance fighter Henriette Bie Lorentzen (née Henriette Wegner Haagaas). A blue plaque, placed by Oslo Byes Vel, commemorates his daughter Henriette at Riddervolds gate 9, where the family lived from 1912.
He was the uncle of the publisher Henrik Groth and the brother-in-law of Nikolai Nissen Paus, George Wegner Paus and Augustin Paus.
Career
He attended the Frederikshald Gymnasium and graduated with the examen artium university entrance exam in 1891. He subsequently studied philosophy, mathematics, natural sciences and law at the Royal Frederick University. He also served as a lieutenant in the Royal Norwegian Navy 1898–1902.
From 1900 he was a lecturer in mathematics at the private gymnasium Frogner School in Oslo. In 1911 he became a member of the management of the school and in 1913 he became one of the school's co-owners. At the time Frogner School's neighbour, the Nissen's Girls' School, was also owned by Frogner School, although they operated as separate schools. He and the other owners sold both schools to Christiania municipality in 1918 and continued to manage them until 1919. In 1917 he was appointed by the King-in-Council as a lecturer at Drammen Higher School, and took office in 1918. In 1920 he left this position to become a lecturer at Frogner School again.
In 1915 he founded Haagaas School, a private gymnasium in Oslo that existed until 1955, and was the school's headmaster until 1946. Haagaas School was the last school in Norway in the tradition of the Heltberg School of the 19th century, offering a fast track to the examen artium (a so-called studentfabrikk, "student factory" or intensive gymnasium). The noted educator Mosse Jørgensen wrote that "if any school had deserved the epithet 'The New Heltberg', it was Haagaas School." According to his former pupil Harald Throne-Holst, Haagaas was characterized by a "strong and active sense of humor." The journal Den høgre skolen (The Higher School) noted that:
He was a co-author and subsequently the sole author of the Haffner og Haagaas series of textbooks in mathematics, which was published between 1925 and 1979 in numerous editions. He was one of the handful of government-appointed examiners in mathematics at the examen artium university entrance exams for several decades. On his death he was described by Aftenposten as a "very widely known educator."
Quotes "Latin, it is mathematics, language mathematics" "If we have two twins and one is named Clariss and the other is named Magdalena, and we say that Clariss equals Magdalena, then that is an equation." "We cannot afford to spend education on the lazy"
Don’t just read it —
keep it.
Full-length biographies made to live with: read them, listen on the way to work, watch them tonight.
- E-book
- Audio
- Video
Instant download · yours to keep · every purchase keeps this site free
Important facts
People in Theodor Haagaas's life
Named in this biography and alive at the same time
Contemporaries
People whose lives overlapped Theodor Haagaas's
Frequently asked questions
Who was Theodor Haagaas?
Norwegian mathematician and educator (1873–1961)
When was Theodor Haagaas born?
Theodor Haagaas was born on 15 June 1873 in Tistedalen.
When did Theodor Haagaas die?
Theodor Haagaas died on 25 December 1961 in Oslo.
What was Theodor Haagaas's occupation?
Theodor Haagaas was a mathematician.
What nationality was Theodor Haagaas?
Theodor Haagaas was Norwegian.
Sources & further reading
Cite this page
APA: Biography.guide. (2026). Theodor Haagaas. https://biography.guide/theodor-haagaas/
MLA: "Theodor Haagaas." Biography.guide, https://biography.guide/theodor-haagaas/.
Chicago: "Theodor Haagaas." Biography.guide. https://biography.guide/theodor-haagaas/.
Data last updated: 2026-09-22 · Spot an error? Report a correction.
Page generated 2026-09-27 05:27 UTC