80 years old * * * has: 80× 365× 24× 60 = 42,048,000 minutes.

Heartbeat: 42,048,000× 70 = 294,336,000 beats (about 2.9 billion beats).

Breathing: Breathe every 8 heartbeats.

So: Breathing times: 2,943,360,000 ÷ 8 = 367,920,000 times (that is, about 368 million times).