Just spent a week and a half teaching fraction equivalence and comparison. Gave the students a quiz today. Let them use multiplication tables, interactive notebooks, etc.
They all failed. Some missed every single question, and it was obvious they had no idea what to do. These kids do the work! What's going on?
I'm starting over on MOnday and reteaching.

When you do your reaching, can you use some real objects? Cut a square in half. Cut another square the same size into 4 pieces. One half and 2 quarters are the same.

Give them squares and scissors to figure out problems.

It's really frustrating when you think they've got something and they lose it that fast.

I'll add Legos to the list of good manipulatives for comparing fractions. Having encountered situations like "if I need an eight long, I can use 2 fours or 4 twos" seems to help them understand. - There have always been kids who struggled with fractions, but I think it's gotten worse as typical play has changed.

I ususally use manipulatives in teaching. I start with maniupulatives, move to visuals (models, pictures), then on to digits. This time because of testing and other events, I did not. Which just goes to show how effective they are in teaching.
On Monday I will start over, and teach the way I usually do. I should know better by now that shortcuts don't work. At least this way I know that with reteaching I covered the concepts!

The twenty years I taught fourth grade, long division had students crying. However, the hardest thing all year in math was comparing fractions. And, yes, we had all the physical manipulatives, used manipulations on the SmartBoard, etc.

I feel for you. Just start over and hopefully the students will understand the second time around.

We've all been there. We've all had lessons fail. Try to reassess before getting to a quiz or graded assignment. I was doing a whole group lesson with mixed numbers the other day and it bombed. I just stopped in the middle of it and didn't continue because it wasn't working. Got them started on their centers, gave myself a few moments to collect myself, and then tackled it in a different way in small groups.

I taught 2nd grade for many years and never thought to represent fractions on a number line. When I got moved to 3rd, it's a standard. It's really hard for them, but I taped number lines in the hallway for fractions this year. I work with groups to place fractions on the various number lines. This is a screenshot of a video I took of them... they were totally wrong with their placement, but they eventually got it through discussion- these conversations were definitely super valuable for them!

Alot. One of my kids asked me today why I use pizzas so much and I told him because it's familiar to them.

I have fraction circles they can use. They are simply printed on construction paper. The masters are from an old Saxon math book. They are cut into the individual pieces and they can lay equivalent fractions on top of each other easily. We also have printed fraction bars on stiff cardstock, and they use those too.

We've also used a number line as well, and as many concrete examples that I can think of.

Good luck and I hope the reteach goes well and they are more successful.