Experiences

We weigh groats- repeating operations on decimal fractions

Aleksandra Pilc

Poland

Primary school

Maths

Teaching in class

Direct

In our school we recently organized a contest - Mathematical formula for health. This year's theme was groats-wealth of properties. Students prepared multimedia presentations about groats. I decided to take advantage of it at the lesson to repeat the material on decimal fractions. I divided students into teams of three (by lot). On a large table I put several types of groats in bowls and transparent plastic cups. In front of each bowl a note with price for 1 kg but without the name of groat. Each group was given the task: mixing together half a cup millet, barley, roasted buckwheat groats and meal of couscous (there were 5 groups and each got a different set of groats). Then they weighed the mixture (I set 3 electronic kitchen scales in the class). How much you will pay for the resulting amount of the mixture, if the price of one kilogram of such a mixture is one fifth of total price for 1 kg of all the groats? Please answer with an accuracy of 0.01. The task checked skill to carry out activities on decimals and ordinary fractions. In addition, students have to repeat the notion of net weight, gross and tare. The biggest problem for children was to recognize some grits, and with this element of play I had to help them a little. After completing the task groups exchanged their tasks and solutions, and checked the correctness of the calculations. I just supervised. Most students enjoyed the moment of weighing groats. Many students have told me that thanks to this they understood the concept of the tare.