I'm not sure where you see velocity. The last major innovation in arethmetic was the introduction of zero when the hindu-arabic numeral system was adopted by medieval western societies. Likewise english grammar isn't exactly a hotbed of churn.

i'm confused by your reply, sorry. what part of my comment are you referring to?

if this is a response to "world is moving fast", i didn't mean "arithmetic is moving fast". i meant technology, the economy, geopolitics, etc. which inevitably changes the learning environment, the home environment, motivation, etc.