Is it possible to add infinitely long decimals? As pupils complete the examples in the ninth instructional activity of this 25-part series, they determine that adding these decimals cannot be done without error. Their task is then to...

Trying to get your class to think of decimals as fractions and vice versa can lead to interesting discussions. After all, we can usually understand quickly that 1/4 is .25 but why is 1/7 not so easy to convert? This activity looks...