Middle School Grade 1 mathematics
Step 4 covers Middle School Grade 1. All 16 activities for this grade band are now translated into English, with the same quizzes and best-score tracking as the Korean site.
🔢 Number & operations
Prime Number Explorer
Click through the Sieve of Eratosthenes and watch multiples get crossed out until only primes remain.
Open English lesson → 🌳Prime Factor Tree Lab
Split a number into a tree of factors, down to nothing but primes.
Open English lesson → 📐Exponents & Laws of Exponents Bridge Lab
See what an exponent means, then discover why multiplying same-base exponents adds them.
Open English lesson → 🌡️Integers & Number Line Lab
Watch an arrow move along a number line to make sense of adding and subtracting positives and negatives.
Open English lesson → 🌡️Integer Multiplication & Division Sign Rules Lab
Decrease a multiplier one step at a time and watch the sign-flipping pattern reveal itself.
Open English lesson →📈 Patterns & relationships
Equation Balance Lab
Keep a balance scale level by applying the same operation to both sides, and solve for x.
Open English lesson → ⇄Direct & Inverse Proportion Lab
Switch between y=kx and y=k/x and compare how differently the graphs behave.
Open English lesson →📐 Shape & measurement
Parallel Lines & Angles Lab
Slice two parallel lines with a transversal and find the vertical, corresponding, and alternate angles.
Open English lesson → ≅Triangle Congruence Conditions Lab
Enter values for SSS, SAS, ASA, RHS, or RHA and watch two triangles overlap perfectly.
Open English lesson → △Polygon Interior Angle Sum Lab
Watch a polygon split into triangles from one vertex to see where (n−2)×180° comes from.
Open English lesson → 🔺Polygon Exterior Angle Sum Lab
Change the number of sides and confirm the exterior angle sum always stays 360°.
Open English lesson → 🧊Cylinder & Cone Volume Lab
Match a cylinder and cone's base and height and confirm the volume ratio is always exactly 3 to 1.
Open English lesson → 🔪Solid Cross-Sections Lab
Rotate and slice cones, cubes, prisms, and more in 3D to see how the cross-section shape changes.
Open English lesson →📊 Data
Mean, Median & Mode Lab
Type in your own numbers and see how the mean, median, and mode each shift.
Open English lesson → 📶Frequency Table Lab
Adjust the class width and watch raw data organize itself into a frequency table and histogram.
Open English lesson → ➗Relative Frequency Lab
Compare two different-sized classes fairly by switching from raw counts to relative frequency.
Open English lesson →