it("should divide temperature degree quantities", () => {
      var qty = Qty("2.5 degF");

      expect(() => { qty.div("0 degF"); }).toThrow("Divide by zero");
      expect(() => { qty.div(0); }).toThrow("Divide by zero");
      expect(Qty("0 degF").div(qty).scalar).toBe(0);
      expect(Qty("0 degF").div(qty).units()).toBe("");

      var result = qty.div("3 degF");
      expect(result.scalar).toBe(2.5 / 3);
      expect(result.units()).toBe("");
      expect(result.kind()).toBe("unitless");

      result = qty.div(3);
      expect(result.scalar).toBe(2.5 / 3);
      expect(result.units()).toBe("degF");
      expect(result.kind()).toBe("temperature");

      // TODO: Should we convert "2 degC" to "degF" before we do the math?
      result = qty.div("2 degC");
      expect(result.scalar).toBe(1.25);
      expect(result.units()).toBe("degF/degC");
    });

 expect(() => { qty.div(0); }).toThrow("Divide by zero");

 expect(function () { qty.div(0); }).toThrow("Divide by zero");