I took about 60 credits - ~8 hours per week each school semester - of Computer Science courses back in the mid 00's at a top state school. Besides the 101 Course, heavy on Java syntax; and Software Architecture where one learns the dark art of Swing, we used pencil, paper, and white boards (even a few chalk boards!) for the rest.
I use concepts like Dijkstra's algorithm and the Turing machine regularly in my job. They are very real to me - more real than any programming language - because I sat for hours taking paper notes off a whiteboard while some OG Computer guru discussed the topic.
If I didn't need tech to learn Computer Science, kids definitely don't need it to learn Algebra.