Arithmetic Operator Puzzles

#1921: 4 _ 6 _ 3 _ 5 = 10 easy #1922: 4 _ 6 _ 4 _ 8 = 7 easy #1923: 4 _ 6 _ 4 _ 2 = 7 easy #1924: 4 _ 6 _ 4 _ 6 = 13 medium #1925: 4 _ 6 _ 4 _ 8 = 16 hard #1926: 4 _ 6 _ 4 _ 3 = -4 easy #1927: 4 _ 6 _ 4 _ 8 = 1 easy #1928: 4 _ 6 _ 4 _ 2 = 1 easy #1929: 4 _ 6 _ 4 _ 6 = -5 easy #1930: 4 _ 6 _ 4 _ 2 = 3 easy #1931: 4 _ 6 _ 4 _ 3 = 18 medium #1932: 4 _ 6 _ 4 _ 3 = 8 easy #1933: 4 _ 6 _ 5 _ 2 = 19 hard #1934: 4 _ 6 _ 5 _ 3 = 14 medium #1935: 4 _ 6 _ 5 _ 3 = -6 easy #1936: 4 _ 6 _ 5 _ 8 = 15 medium #1937: 4 _ 6 _ 5 _ 3 = 10 easy #1938: 4 _ 6 _ 6 _ 4 = 13 medium #1939: 4 _ 6 _ 6 _ 9 = 8 medium #1940: 4 _ 6 _ 6 _ 4 = -5 easy #1941: 4 _ 6 _ 6 _ 8 = 18 hard #1942: 4 _ 6 _ 6 _ 9 = 16 hard #1943: 4 _ 6 _ 7 _ 3 = 18 hard #1944: 4 _ 6 _ 8 _ 3 = 20 hard #1945: 4 _ 6 _ 8 _ 4 = 16 hard #1946: 4 _ 6 _ 8 _ 4 = 1 easy #1947: 4 _ 6 _ 8 _ 1 = 4 easy #1948: 4 _ 6 _ 8 _ 2 = 5 easy #1949: 4 _ 6 _ 8 _ 2 = 1 easy #1950: 4 _ 6 _ 8 _ 3 = 6 easy #1951: 4 _ 6 _ 8 _ 3 = 1 easy #1952: 4 _ 6 _ 8 _ 4 = -1 easy #1953: 4 _ 6 _ 8 _ 5 = 8 medium #1954: 4 _ 6 _ 8 _ 5 = -2 easy #1955: 4 _ 6 _ 8 _ 5 = 15 medium #1956: 4 _ 6 _ 8 _ 6 = 9 medium #1957: 4 _ 6 _ 8 _ 6 = -3 easy #1958: 4 _ 6 _ 8 _ 6 = 18 hard #1959: 4 _ 6 _ 8 _ 7 = 10 medium #1960: 4 _ 6 _ 8 _ 7 = -4 medium #1961: 4 _ 6 _ 8 _ 8 = -5 medium #1962: 4 _ 6 _ 8 _ 9 = 12 hard #1963: 4 _ 6 _ 8 _ 9 = -6 medium #1964: 4 _ 6 _ 8 _ 3 = 16 hard #1965: 4 _ 6 _ 9 _ 3 = 6 medium #1966: 4 _ 6 _ 9 _ 6 = 8 medium #1967: 4 _ 6 _ 9 _ 3 = 8 easy #1968: 4 _ 6 _ 9 _ 6 = 16 hard