Hundreds of mourners packed the streets to pay their respects at the funeral which was broadcast on Iranian state TV.
Coffins draped in the flag of the Islamic Republic were carried through the crowds, as a voiceover recounted the grief of mothers and fathers who had lost their daughters.
Iranian officials said the school was hit by three missiles on Saturday morning. It was located about 600m (1970ft) from an IRGC base.
The six-day working week in Iran runs from Saturday to Thursday, with Friday being the only official day of rest, meaning the school was likely occupied when it was hit.
Iran’s President Masoud Pezeshkian called the incident a “barbaric act” and “another black page in the record of countless crimes committed by the aggressors”.
The country’s Foreign Minister Seyed Abbas Araghchi posted a photo on social media of graves being dug for 160 people, with the comment: “This is how ‘rescue’ promised by Mr Trump looks in reality.”