2/2 Can't emphasize this finding too strongly: It's not just that explicit instruction of procedures is less useful than helping kids to construct mathematical principles for themselves. It's that explicit instruction of procedures can do damge by impeding understanding.
1/2 Teach kids principles AND procedures in math? Nope. This 1991 study found that the destructive effects of step-by-step direct instruction aren't offset by adding richer content: https://t.co/bpz4PCtvPd. And this study 25 yrs later confirmed it: https://t.co/7YF8wYiBEq...
3/4 Two doses of mRNA #COVID19Vaccines provide reasonable protection against severe Omicron disease (~64%-86% vaccine effectiveness), which ↓ over time since 2nd dose. However, protection ↑ to ~90% or more after an mRNA #BoosterDose.