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.

What grade level is 4.MD.1 taught?

This standard is part of the Grade 4 curriculum in Mississippi College- and Career-Readiness Standards for Mathematics.

Are there practice problems for 4.MD.1?

Yes, there are 3 practice problems available for 4.MD.1 with worked examples.

What learning resources are available for 4.MD.1?

There are 36 Khan Academy resources available for 4.MD.1, including 15 videos, 14 exercises, 7 articles.

4.MD.1: Know relative sizes of measurement units within one system of units including km, m, cm, mm; kg, g, mg; lb, oz.; l, ml; hr, min, sec. Within... | Mississippi College- and Career-Readiness Standards for Mathematics

Know relative sizes of measurement units within one system of units including km, m, cm, mm; kg, g, mg; lb, oz.; l, ml; hr, min, sec. Within a single system of measurement, express measurements in a larger unit in terms of a smaller unit. Record measurement equivalents in a two-column table. For example, know that 1 ft is 12 times as long as 1 in. Express the length of a 4 ft snake as 48 in. Generate a conversion table for feet and inches listing the number pairs (1, 12), (2, 24), (3, 36),…

Example Problems

The image files captured by a drone have a mean size of

2.8 \text{ megabytes}

with a standard deviation of

0.6 \text{ megabytes}

.

What will be the mean of the distribution of file sizes in kilobytes?

1 \text{ megabyte}

equals

1024 \text{ kilobytes}

The distribution of heights of the twelve-year-old boys on Tim's rugby team had a mean of

150 \text{ cm}

and a standard deviation of

10 \text{ cm}

.

What will be the mean of the distribution of heights in feet?

1 \text{ cm}

approximately equals

0.033 \text{ ft}

A litter of newborn kittens had weights with a mean of

420 \text{ grams}

and a standard deviation of

60 \text{ grams}

.

What will be the mean of the distribution of weights in pounds?

1 \text{ gram}

approximately equals

0.0022 \text{ pounds}

Khan Academy Resources

Metric units of length review (mm, cm, m, & km)US Customary units of length review (in, ft, yd, & mi)Metric units of mass review (g and kg)Metric units of volume review (L and mL)US Customary units of weight review (oz & lb)Converting units of time review (seconds, minutes, & hours)US Customary units of volume review (c, pt, qt, & gal)Estimating time (seconds, minutes, and hours)Convert to smaller units (oz and lb)Estimate volume (milliliters and liters) Convert to smaller units (mL and L)Estimating length (in, ft, yd, and mi)Estimating mass (ounces and pounds)Estimating volume (cups, pints, quarts, and gallons)Estimating length (mm, cm, m, km)Convert to smaller units (g and kg)Convert to smaller units (mm, cm, m, & km)Estimate mass (grams and kilograms)Convert to smaller units (sec, min, & hr)Convert to smaller units (in, ft, yd, & mi)Convert to smaller units (c, pt, qt, & gal)Converting yards into inches Converting pounds to ounces How to convert kg to mg and T to oz Convert liters to milliliters Converting metric units of length Metric system: units of distance Choose pounds or ounces to measure weight U.S. customary units: weight Metric system: units of volume Finding reasonable unit of measurement example Converting units of time U.S. customary units: fluid volume U.S. customary units: distance Converting feet to inches Metric system: units of weight

1-on-1 AI tutoring aligned to 4.MD.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 →