Quoto

Practice / Trainers

Trainers

Timed trainers for mental arithmetic, sequences, probability, fractions and Fermi estimation, all keyboard-first.

  • 80 in 8

    The classic screening test: 80 questions, 8 minutes, a wrong answer costs a point.

  • Mental arithmetic

    Addition, subtraction, multiplication and exact division, against the clock.

  • Sequences

    Six terms are shown. Find the seventh: arithmetic, geometric, recursive or mixed.

  • Probability and EV

    Dice, coins, cards and urns: probabilities and expected values worked out in your head.

  • Fermi estimation

    Order-of-magnitude questions. Within a factor of 2 counts as right.

  • Intervals

    Give a low and a high bound. A narrow range that holds the answer scores most; a miss scores 0.

  • Likelihood list

    Rank three to five outcomes of the same dice, coins, cards or urn from most to least likely.

  • Order books

    Read a book of bids and offers: what a market order costs, where the edge is, the profit after fills.

  • Target number

    Make the target from four numbers, each used once, with + − × ÷ and brackets.

  • Calculus

    Derivatives, tangents, integrals, extreme values, limits and series of polynomials, worked by hand.

  • Linear algebra

    Determinants, entries of an inverse, whole-number eigenvalues and linear systems on 2 × 2 and 3 × 3 matrices.