         expected = @exp_builder(open_expression: {open_expression: [8]})
         expect(exp).toBeAnEqualExpressionTo expected
 
-    describe "when the manipulation to be manipulated has an exponentiation as its last element", ->
+    describe "when the equation has as its last element an exponentiation ", ->
       describe "with no power", ->
         beforeEach ->
-          @exp = @exp_builder('^': [10, null])
+          @exp = @exp_builder('^': [10, {open_expression:  null}])
 
         it "inserts the number into the exponentiation", ->
           new_exp = @manip.append_number.build(value: 11).invoke(@exp)
-
           expected = @exp_builder('^': [10, {open_expression: 11}])
           expect(new_exp).toBeAnEqualExpressionTo expected
 

      exp = @exp_builder(1)
      new_exp = @manip.append_multiplication.build().invoke(exp)
      expect(new_exp.last() instanceof @math.components.multiplication).toEqual true

    it_inserts_component_into_the_last_nested_open_expression(
      name: 'multiplication'

      expect(new_exp).toBeAnEqualExpressionTo @exp_builder([])

    it "correctly handles nested open subexpressions", ->
      exp = @exp_builder(open_expression: {open_expression: null})
      new_exp = @manip.close_sub_expression.build().invoke(exp)
      expected = @exp_builder(open_expression: [[]])
      expect(new_exp).toBeAnEqualExpressionTo expected

  describe "appending multiplication", ->
    it_plays_manipulation_role (test)->
