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.

MA.3.NSO.2.1

Add and subtract multi-digit whole numbers including using a standard algorithm with procedural fluency.

Example Problems

Evaluate:

-10 - (-5) + 2

Evaluate:

7 + (-3) + (-4)

Evaluate:

-8 - 3 + 8 + (-3)

Khan Academy Resources

Addition, subtraction, and estimation: FAQ Add within 1000 Subtract within 1000 Subtract on a number line Estimate to subtract multi-digit whole numbers Estimate to add multi-digit whole numbers Select strategies for subtracting within 1000 Break apart 3-digit subtraction problems Add on a number line Add and subtract within 1000 word problems Add using groups of 10 and 100 Break apart 3-digit addition problems Select strategies for adding within 1000 Find the missing number (add and subtract within 1000)Subtraction by breaking apart Estimating when subtracting large numbers Adding 3-digit numbers Breaking apart 3-digit addition problems Subtracting 3-digit numbers (regrouping) Worked example: Subtracting 3-digit numbers (regrouping twice)Worked example: Subtracting 3-digit numbers (regrouping from 0)Methods for subtracting 3-digit numbers Using place value to add 3-digit numbers: part 1 Adding and subtracting on number line Addition using groups of 10 and 100 Three digit addition word problems Worked example: Subtracting 3-digit numbers (regrouping) Estimating when adding multi-digit numbers Three digit subtraction word problems Missing number for 3-digit subtraction within 1000 Missing number for 3-digit addition within 1000 Using place value to add 3-digit numbers: part 2

1-on-1 AI tutoring aligned to MA.3.NSO.2.1. Instant help for students, real-time insights for teachers.

Used in classrooms by 100,000+ students at Baltimore County, Plano ISD, Deer Valley USD, KIPP, and districts nationwide.

Free for teachers, forever →