How many years were there from Abraham's call to the Exodus?
The time from Abraham's call until Israel's departure from Egypt totaled 430 years, as God had mandated. This fixed span covers the entire period, with the harsh slavery in Egypt occupying only a portion of it, not the full 400 years.
Les teaches that the 430 years God mandated from the call of Abraham until Israel left Egypt is the total span. He points out that the period from Joseph's death and Moses' birth to the Exodus was 215 years, which is exactly halfway through the 430 years. Therefore, the abject slavery in Egypt did not last the whole 400 years, nor even 200 years; it was more like 140 or 150 years.