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.

3.MD.C.7.d

Recognize area as additive. Find areas of rectilinear figures by decomposing them into non-overlapping rectangles and adding the areas of the non-overlapping parts, applying this technique to solve real world problems.

Example Problems

Function

f

is continuous and decreasing.
We're interested in the area under the curve between

x = -8

and

x = -2

, and we're considering using left and right Riemann sums to approximate it.

Order the following areas from least (on the left) to greatest (on the right).

Actual area under the curve
Left Riemann sum
Right Riemann sum

Function g is continuous and increasing.
We're interested in the area under the curve between

x = 0

and

x = 12

, and we're considering using left and right Riemann sums to approximate it.

Order the following areas from least (on the left) to greatest (on the right).

Actual area under the curve
Left Riemann sum
Right Riemann sum

This table gives select values of the continuous and increasing function

f

x	f(x)
-7	17
-5	24
-3	34
-1	40

We're interested in the area under the curve between

x = -7

and

x = -1

, and we're considering using left and right Riemann sums, each with three equal subdivisions, to approximate it.

Order the following areas from least (on the left) to greatest (on the right).

Area Type
Actual area under the curve
Left Riemann sum
Right Riemann sum

Khan Academy Resources

Decompose figures to find area Understand decomposing figures to find area Decomposing shapes to find area: subtract Decomposing shapes to find area: grids Decomposing shapes to find area: add Area word problem: house size

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