1. Where a pension granted under the Act respecting the Teachers Pension Plan (chapter R-11), after 10 years of credited service, except that granted to a child and those provided for in sections 50 and 53 of the Act, is less than the benefit calculated in accordance with section 2 of this Plan, the beneficiary shall be paid a benefit equal to the difference between the benefit fixed in section 2 and that which would have been paid under the Teachers Pension Plan.