Helping Students Understand Measuring Using Benchmark Fractions

This summer I taught a fourth grade group in a special education extended year program. This was a great experience for me, and I was reminded how much I like teaching elementary children.

In math we worked on reinforcing basic computation and numbers and operations. However, as an integrated learning science project, we grew alfalfa sprouts, keeping a written class journal of the progress. So each day, in addition to describing the growth of the sprouts, I asked the children to measure their length. The rulers we used had only half and quarter inches on them, but initially the students would give their answer to the nearest inch. This gave me the impetus for convincing the kids they needed to use all the marks on the ruler, and not just the numbered inch marks.

So we started learning the benchmark fractions of ¼, ½, and ¾ .There was one activity that especially helped to get students to apply what they had learned. I brought in some rope (perhas it is more accurately called twine) and had each child get a partner to cut a piece that was their height. They laid down on the floor and their partner measured them against the rope and cut it for them. Then their rope was called by their name. So my rope would have been called a Marsha. I then instructed students to find and mark half by folding the rope in two equal sections. We marked the spot using masking tape. So on my rope I would have found half a Marsha. We then found ¼ and ¾ marks. In order to do this, one end of the rope must be designated as the starting point or “zero” and the other end as “one”.

Then I posed a question on the board. How many of you does it take to go from the classroom door to the gym door? I wrote each child’s name on the board, giving them a space to report their own findings. They took their own ropes and measured how many could fit down the hallway to the gym. They found it easier to do with the help of a partner. After they had written their findings on the board, I asked them why the answers were all different. Had someone done something wrong? They knew that it was because they were all different heights. I then explained that we need a common system of measurement, and that is why we use inches feet etc.

I had gone over the benchmark fractions for several days, but after we did this activity, they started to remember them and were using them in measurement with more ease. It was an active learning project that made an impression.