CREATE TABLE "complete_formula_one_world_championship_" (
  "year" real,
  "entrant" text,
  "chassis" text,
  "engine" text,
  "points" real
);

Question: What is the year with a Kurtis Kraft 500a chassis, and less than 1.5 points?
SQL: SELECT SUM("year") FROM "complete_formula_one_world_championship_" WHERE "chassis"='kurtis kraft 500a' AND "points"<1.5;

Question: What is the year with a kurtis kraft 500a chassis?
SQL: SELECT SUM("year") FROM "complete_formula_one_world_championship_" WHERE "chassis"='kurtis kraft 500a';