Looks like the math sequencing is unusual.
“Regular” and “advanced” students take 6th and 7th grade math, then they split into different sequences in 8th grade, and then “advanced” students split into +1 and +2 groups in 10th grade:
- “Regular” +0: 8th grade math → geometry → algebra 1 → algebra 2 → precalculus
- “Advanced” +1: algebra 1 → geometry →
- +1: algebra 2 → precalculus → calculus AB
- +2: algebra 2 + precalculus → calculus AB → calculus BC
(listing the mainline path to calculus, not the off-ramps to statistics shown in the chart)
But all take geometry in 9th grade.