Decimal × & ÷
Understand decimal × integer and decimal ÷ integer: compute as whole numbers first, then place the decimal point; keep the quotient's point aligned with the dividend's.
Area of Polygons
Derive the area formulas for parallelograms, triangles and trapezoids by cutting, rotating and translating — a first taste of the transformation idea in mathematics.
Factors & Multiples
Meet factors and multiples: hunt for them on the number chart, learn the divisibility tricks for 2, 5 and 3, and sieve out primes and composites.
Volume
Count unit cubes layer by layer to measure a solid, discover the cubes hiding underneath, and build the formula V = length × width × height.
Coordinate Plane
Plot and read points in the first quadrant: across first, then up, locating any spot with an (x, y) pair; then see how a sliding shape changes its vertices.
Powers of Ten
Feel how place values shift when you multiply by 10, 100 or 1000: every digit slides along the chart; then meet exponents and the zeros-count trick.