past paper Mar -June 17

The School Uniform Company (SU Co) manufactures school uniforms. One of its largest contracts is with the Girls’ Private School Trust (GPST), which has 35 schools across the country, all with the same school uniform.
After a recent review of the uniform at the GPST schools, the school’s spring/summer dress has been re-designed to incorporate a dropped waistband. Each new dress now requires 2·2 metres of material, which is 10% more material than the previous style of dress required.

in the solution they have divided 2.2metres by 1.1

but 10% is 0.10 how can i get 1.1 ???