Legs 9 and 12. Is the hypotenuse 21?MYP Year 9 · Pythagoras' theorem, question 2
Share 150 in the ratio 2 : 3. Is the larger share 50?MYP Year 8 · Sharing in a ratio, question 1
x² = 12x. Can you divide both sides by x?MYP Year 10 · Solving by factorising, question 3
Is √63 + 2√7 equal to 3√7?MYP Year 10 · Simplifying surds, question 5
8 seeds, each grows with probability 0.4. P(at least 3 grow)?IB Diploma · The binomial distribution, question 4
10-second challenge: 25% of 88, no calculatorMYP Year 7 · Percentage of an amount, question 3
Lean a parallelogram over. Does the area change?MYP Year 7 · Triangles and parallelograms, first figure
Spot the mistake: (8 × 10⁹) ÷ (2 × 10³)MYP Year 9 · Calculating with scientific notation, question 3
10-second challenge: P(binoculars | camera)MYP Year 10 · Conditional probability, question 2
Move one point. What happens to r?IB Diploma · Correlation, the scatter figure
Spot the mistake: f′(2) for 2x⁴ − 3x³ + 6x − 5IB Diploma · Differentiating powers, question 1
Move point B. What happens to the gradient?MYP Year 9 · Gradient, the first figure
Spot the mistake: expand 2(3x + 5) − 4(x − 2)MYP Year 8 · Expanding brackets, question 8
10-second challenge: 16 to the power ¾IB Diploma Analysis and Approaches · Log laws, question 1
Spot the mistake: the first 5 terms of 243, 81, 27, …MYP Year 11 · Adding a geometric sequence, question 3
More: every lesson, Year 7 to the Diploma423 lessons, the first of every unit free