An initiatory or a referendary petition shall be signed by not less than fifteen (15) per cent of the registered electors of the city who have signed said petition within six (6) months before the date of filing the petition with the Clerk. Before being circulated for signatures, all such petitions may be approved as to form by the Clerk. No such petition need be on one paper, but may be the aggregate of two (2) or more petition papers. Each signer of a petition shall sign his name in ink or indelible pencil, and shall place thereon, after his name, the date and his place of residence by street and number, or by other customary designation. To each petition paper there shall be attached a sworn affidavit by the circulator thereof, stating the number of signers thereto and that each signature of the person whose name it purports to be, and that it was made in the presence of the affiant. Such petition shall be filed with the Clerk who shall, within ten (10) days, canvass the signatures thereon to determine the sufficiency thereof. If found to contain an insufficient number of signatures of registered electors of the city or to be improper as to form or compliance with the provisions of this section, the Clerk shall notify forthwith the person filing such petition, and ten (10) days from such notification shall be allowed for the filing of supplemental petition papers. When found sufficient and proper, the Clerk shall present the petition to the Commission at its next regular meeting.