The use of standardised tests as a central tool in education policy has in recent decades become a common feature of many national education systems. In 2002 the Israeli Ministry of Education introduced new mandatory state tests for primary and middle schools. The article describes the adoption of these low-stakes tests and assesses their impact on schools using quantitative and qualitative data. It shows that the tests have unintended negative consequences similar to those reported in studies on high-stakes tests in other countries. An explanation for these findings, based on the notion of "power of numbers," is proposed and discussed.