‹
🧮
Number Sense
· Formula🧮 Formula Reference Sheet
Place value: 4327 = 4×1000 + 3×100 + 2×10 + 7×1 Round: 487 ≈ 500 (to nearest 100) Estimate: 38 × 22 ≈ 40 × 20 = 800 Compare fractions: cross-multiply
⚡ Example per formula
Place value: 4327 = 4×1000 + 3×100 + 2×10 + 7×1
↳4327 → 4 thousands, 3 hundreds, 2 tens, 7 ones
Round: 487 ≈ 500 (to nearest 100)
↳487 → nearest 100 = 500
Estimate: 38 × 22 ≈ 40 × 20 = 800
↳38 × 22 ≈ 40 × 20 = 800
Compare fractions: cross-multiply
↳5/8 vs 3/5 → 25 vs 24 → 5/8 bigger
✏️
Practice Exercises →
5 graded problems · AI checks each step