We introduce a new family of one-player games, involving the movement of coins from one configuration to another. Moves are restricted so that a coin can be placed only in a position that is adjacent to at least two other coins. The goal of this paper is to specify exactly which of these games are solvable. By introducing the notion of a constant number of extra coins, we give tight theorems ch...

Drawings from memory of a penny, nickel, dime, and quarter were obtained from 125 undergraduates. The modal recalls for the heads of all four coins were identical, suggesting that a schema for coins exists. In an attempt to have the schema produced directly, another 75 students designed either a 2-, 7-, or 20-cent piece that would fit into our present currency. The modal drawing for this task w...

This paper addresses the 3D acquisition of historical coins and evaluates its benefits over the current documentation method by means of 2D images. We present preliminary results on creating full 3D models of coins from the Roman and medieval times using a state-of-the-art active stereo scanning device. Furthermore, we discuss the results from numismatic point of view and highlight the differen...

This paper addresses a popular topic in science teaching and competitions for primary secondary school students. Experiments with colliding coins are relatively easy to perform therefore lessons. We used the idea competition we organized pupils aged 6 13 years. The is based on few experiments that participants have carry out before competition. Some years ago, 10- 11-year-old had experiment coi...

This paper studies the trade-off between two different kinds of pure exploration: breadth versus depth. We focus on the most biased coin problem, asking how many total coin flips are required to identify a “heavy” coin from an infinite bag containing both “heavy” coins with mean ✓ 1 2 (0, 1), and “light" coins with mean ✓ 0 2 (0, ✓ 1 ), where heavy coins are drawn from the bag with proportion ↵...

OBJECTIVES To determine the quantity and quality of bacterial and fungi on money coins and to identify those that could pose a public health risk. DESIGN Random sampling of coins from subjects within predetermined categories. SETTING Westlands division of Nairobi Metropolitan province. SUBJECTS Twenty-shilling coin samples were collected from matatu (a common commuter vehicle in Kenya) ta...