var fDesc=new Array(); fDesc[0] = "Mental Arithmetic has been designed to provide pupils with unlimited practice in the fundamentals of mathematics by teachers David Benjamin and Justin Dodd, the UK’s leading experts on the use of software in the classroom.

The computer can generate endless sequences of new problems.

Answering questions against the clock becomes almost compulsive for pupils.

Upon completion of a set of questions, pupils can print out a certificate to record their achievement."; function tShowHide(id, show) { var s = document.getElementById("desc"); if ((s.innerHTML.length<=212 || show==1) && show!=2) { s.innerHTML = fDesc[id]; if (document.getElementById('m1')) document.getElementById('m1').style.display='none'; if (document.getElementById('m2')) document.getElementById('m2').style.display='none'; if (document.getElementById('more_txt')) document.getElementById('more_txt').style.display='inline'; } else { s.innerHTML = ''; } }