Manitoba, Saskatchewan and New Brunswick are among the lowest-scoring provinces on both assessments.
When governments closed schools and disrupted learning, many families rediscovered the important contributions schools make to modern society.
In science, Alberta outscored highly-ranked countries including Estonia and Finland.
In each subject, the country's average scores have been declining over time.
The urbanized region represents only 13 per cent of the country's total population.
Among the provinces, B.C. had the second-largest decline in science.
During the pandemic, most provinces suspended their testing programs.
The province's students were behind in math, science, and reading even before the pandemic.