An initiatory or a referendary petition shall be signed by registered qualified electors of the city in number equal to fifteen (15) per cent of the electors of the city voting for the councilman receiving the highest number of votes at the last regular city election held prior to the filing of the petition. Before being circulated for signatures, all such petitions shall 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 thereon is the genuine 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 names thereon to determine the sufficiency thereof. If found to contain an insufficient number of names of qualified electors of the city, or to be improper as to form or compliance with the provisions of this section, the City Clerk shall notify the person filing such petition forthwith 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 Council at its next regular meeting.