“The Number Race” is an adaptive game designed to improve number sense. We tested its effectiveness using a cross‐over design in 53 low socioeconomic status kindergarteners in France. Children showed improvements in tasks traditionally used to assess number sense (numerical comparison of digits and words). However, there was no improvement on non‐symbolic measures of number sense, suggesting that rather than being in number sense per se, the improvement was in number sense access; or links between symbolic and non‐symbolic representations of number. Focused adaptive interventions such as this may contribute to reducing the socioeconomic gap in math achievement.

A probe tack test apparatus is designed to characterize the tack of carbon-epoxy prepreg. Tests are performed on both pure resin and prepreg. The maximum debonding force seems to be a relevant measure of tack. First, results show that the response of pure resin is similar to that of viscous silicon oil. Second, the shape of the response curve obtained for prepreg beyond the maximum value of the debonding force is mainly due to structural effects. Third, the influence of contact force, contact time, debonding rate, probe temperature and ageing conditions on the prepreg tack is investigated in relation with physical phenomena involved in the debonding phase.

This article deals with the effect of temperature variations on crack tip kinematics in rubbers, especially in crystallising rubbers. In such materials, the high deformation level encountered at the crack tip engenders the formation of crystallites. As a consequence, the crack tip is reinforced and resists crack growth. However, this phenomenon is significantly affected by variations in material temperature. This is classically observed at the macroscopic scale in terms of crack propagation rate and path. In this study, the effect of temperature is studied at the local scale, by measuring the change in the kinematic field at the crack tip during thermal cycles. Results show that, in crystallisable natural rubber, the effect of temperature depends on the stretch ratio attained in the zone under consideration. In slightly stretched zones, the stretch ratio increases with the increase in temperature, whereas it decreases in highly stretched zones. This highlights the competition between the effects of the variations in internal energy and in entropy on the thermomechanical response. Moreover, if crystallites form in highly stretched zones, the increase in temperature leads to crystallite melting, which increases the stretch ratio. This is explained by the fact that crystallites act as fillers by concentrating the stress and therefore by increasing the apparent stiffness of the material.