A randomized controlled trial in Sierra Leone found that students assigned to use Gemini Guided Learning during teacher-led math lessons recorded higher assessment scores than students receiving standard instruction. The preregistered trial involved 1,763 Grade 7 and Grade 8 students across 48 classrooms in 12 government-supported junior secondary schools in Port Loko District. The intervention ran from October 6 to December 5, 2025, with teachers incorporating Gemini into two of four weekly math periods for a target of 12 hours over eight weeks. Results released in June 2026 showed an intent-to-treat effect of 0.258 standard deviations on math scores, estimated as equivalent to moving a student from the 50th to the 60th percentile. Students who entered with stronger math skills recorded the largest gains. The study is the first in a planned international series of preregistered trials. Google DeepMind and Fab AI released the teacher training materials and a rapid RCT playbook.