The Short Version
The figure of 428 does not represent the total number of Hindu temples in Pakistan's territory at the 1947 partition. The primary source containing this number (Hinduism Today) uses it to describe temples that remained functional for a period after partition, while placing the partition-era total at 1,288 registered temples. No independent scholarly or census source corroborates 428 as a partition-time estimate, and the most authoritative source (Carnegie Endowment) offers only a broad range of 300–500 "major" temples — a different category entirely.