Is Goblins free for teachers?

Yes. Goblins offers a generous free tier that includes 1 live feedback assignment per week, insights on student mastery and replays, and the ability to upload your own content. The Max plan adds unlimited assignments, superadaptive mode, grade exports, standards growth reports, and SSO/LMS integration, with per-student pricing for schools and districts.

How does Goblins work?

Three simple steps: (1) Share an assignment from thousands of standards-aligned topics using a share code. (2) Students speak and draw their thinking naturally, and Goblins responds with Socratic questioning that sounds just like their teacher. (3) Teachers get real-time formative insights showing what students struggle with and suggestions to inform instruction.

Does Goblins prevent cheating?

Yes. Goblins uses a purpose-trained AI model that evaluates cheating signals in real time. It can detect when students are copying answers, using external tools inappropriately, or not genuinely working through problems. Copy-pasting answers is also blocked.

Can I use my own voice with Goblins?

Yes. Teachers can record their voice and take a selfie to create a custom 3D avatar in about 30 seconds. Students then hear help in their own teacher's voice and see a familiar face, making the experience more personal and effective.

What math levels does Goblins cover?

Goblins covers math from Grade 5 through AP Calculus, including thousands of standards-aligned topics. Teachers can also upload their own content for custom assignments at any level.

Is Goblins FERPA compliant?

Yes. Goblins is FERPA and state compliant. Student data privacy and security are a top priority.

Does Goblins support English Language Learners?

Yes. Goblins supports 30+ languages so teachers don't have to translate every worksheet. It is especially helpful for ELL students who need accessible math instruction in their native language.

SR.DSR.4.6

Use simulations to investigate associations between two categorical variables and to compare groups.

Example Problems

Three office buildings surveyed a random sample of employees about their recycling habits. Here are the results:

Building	Always	Sometimes	Never	Total
Building A	50	20	10	80
Building B	40	30	10	80
Building C	30	25	15	70
Total	120	75	35	230

They want to perform a χ² test of homogeneity on these results.

What is the expected count for the cell corresponding to Building B employees who never recycle?
Round your answer to the nearest hundredth.

Kira surveyed three neighborhoods about pet ownership. Each neighborhood provided a random sample of households. Here are the results:

Neighborhood	Dog	Cat	Neither	Total
Neighborhood A	35	22	13	70
Neighborhood B	28	30	12	70
Neighborhood C	24	18	18	60
Total	87	70	43	200

They want to perform a χ² test of homogeneity on these results.

What is the expected count for the cell corresponding to households in Neighborhood C that own a cat?

Librarians at three branches randomly sampled patrons and asked which types of books they had read in the past month. Here are the results:

Library branch	Fiction	Nonfiction	Both	Total
North branch	40	25	15	80
East branch	30	20	10	60
South branch	35	30	15	80
Total	105	75	40	220

They want to perform a χ² test of homogeneity on these results.

What is the expected count for the cell corresponding to East branch patrons who read Fiction?
Round your answer to the nearest hundredth.

Khan Academy Resources

Interpret results of simulations Random numbers for experimental probability Statistical significance of experiment

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