Teaching children to mindlessly follow algorithms is such a frustrating thing to try to combat as a teacher- these kids often resist attempts to make math make sense!
#Teachmath
@tdsbmath.bsky.social

Then the student made an error with his equivalent fractions, and got an incorrect answer, and did not know that his answer made no sense- it’s much too small

Why do common denominators at all? 3/6 = 1/2, 6/3 =2, so the answer is 2 1/2

He made a common denominator of 18, which you would only do if you had learned a procedure (multiply the denominators to find your common denominator)
If you want a common denominator, 6 is a much easier and more logical choice

Even worse, the student wanted to show me the great math he had learned in his program
He was trying to add 3/6 and 6/3

Here is some thinking from a grade 3 student recently
This student solved this problem by standard regrouping, but then just counted back from 15 to solve 15-8
Why do the regrouping, if you are just going to count?

And student work
Great job!

Practice questions for students

And some exit tickets
See how done students thought visually, and some with a T-table

Great student thinking!

Student solutions
#visualmath
@tdsbmath.bsky.social

and get images like this