Dicing with fractions

Well, we’ve finally got to the end of unit E2 and it has been a hard slog. They just find fractions so hard in all years and it doesn’t get any easier by the time you get to year 5.

We’ve just about cracked finding fractions and percentages of amounts but I was still concerned by their real understanding of equivalent fractions and the part played by the numerator and denominator.

We had a shortened maths lesson today straight after a very lively assembly so there was no way I was going to deliver my planned lesson. I decided to play an old game and try a new variation of it.

For years I have used making dice numbers as a starter activity. Basically the children draw a 4 square grid in their books and you roll a 0-9 dice. The children have to decide which place to put the digit. The aim is to make the biggest (or smallest) number and is a fun way of reinforcing place value. You can make HTU numbers or 10000 although I think the value is lost after that.

In Primary Maths – Teaching for Understanding by Barmby et al I saw the idea of using the same game to create fractions (pp80-81) and thought that today would be a good day to try it.

We began by playing the original game just to remind them of the point of the exercise. Then I drew the grid for 2 fractions with a greater than symbol between them and told them they had to create 2 fractions, the first being greater than the second.

The 4 dice rolls produced numbers 1, 4, 8, 3 and I was amazed at how many children used the 1 as a denominator which seemed to show a real lack of understanding. Only one child managed to place his 4 digits in positions to generate 2 fractions that made the equation correct and that was by sheer luck.

We then discussed what possibilities there were to create correct statements to lots of cries of “I get it now!”. We played the game again and about a third of the class managed to get a correct statement. Again, we looked at all the possibilities we could have created.

On the third game I stopped after the third dice roll and we discussed what numbers the children were hoping for to make their statements correct. This generated some real discussion about equivalent fractions as the children worked out which numbers would give them a winning equation.

I think that all the children ended the session with a much better understanding of fractions and they all enjoyed the session. I overheard one of my less enthusiastic pupils telling another child that “Maths was really great today” and that was 40 minutes after the lesson had ended.

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