位取り表：専門家設計のデジタル操作で数学をマスターしよう

Experience grouping and ungrouping in our decimal number system with this interactive place value chart. Touch the chart to create tokens and move them around with your finger. Is this always possible? Remove tokens by moving them to the top of the chart. Shake your iPad or iPhone to remove all of them. Some activities supported by this place value chart: - How can you create large numbers using the least number of tokens? - How can you remove tokens quickly without shaking the device? - What happens if a token is moved from the hundreds to the ones? And what happens if you first move it to the tens place and then to the ones? This brand new version features new options to show totals, both as a number and in written english. Furthermore it is possible to use it for decimal fractions. The educational design of this interactive place value chart has been developed by Prof. Ulrich Kortenkamp (Didactics of Mathematics, University of Potsdam, Germany) and Prof. Silke Ladel (Didactics of Primary Education, Mathematics, Saarland University, Germany). It supports the development of mental concepts for place values in decimal systems and targets elementary and primary and lower secondary education.