I am trying to design a grade-appropriate questions for 6th grade using statistics.

What is the median, mode and average of the number of chocolate chips in a batch of cookies?

Fantastic idea. Thank you.

Have them form tasting panels,
Each panel tests four different brands of cookies.

Let them score each cookie brand on different qualities on a 1 thru 5 scale:

crunchiness, freshness, chocolateness, overall taste, visual appeal, aroma appeal.

Then let them calculate average scores for each brand on each quality.

Let them add up the scores and divide by price.
Let them indicate how important certain aspects are and come to weighted scoring.

And – although you don’t need to address this – please don’t teach them poor research skills by making even scales from negative to positive, since these are at best ordinal and not linear, so they don’t allow averaging. (A personal peeve.)

Measure of variance (standard deviation) is also appropriate and easy to diagram.

You can use a table with different categories for example:
Calories/sugar/fat
Recipe 1: 100/50/75
Recipe 2: 225/41/34