Fractions

For our fraction warm up today we counted by 1/4 around our table groups. To make it more interesting or a bigger challenge we added clapping on the whole numbers and then stomping on the half numbers. We then tried it as a whole class with 16 people present. The next challenge was to put on a number line where we’d end up if we went 3 times around the room, or 5 times around the room counting by 1/4. The final thought experiment was, if we counted by 1/5 how many times around the room would we need to get to a number between 20 and 30? It was a good introduction and got us thinking about unit fractions.

Next we got up to the boards and tried to put price tags on these pieces of cake. A very creative baker decided to cut cake in some interesting ways. Each cake costs 60$.

Groups had different approaches to their calculating. Some looked at fractions, some divided the 60 up, and some did both! Groups were drawing extra lines to subdivide pieces and help them figure things out.

We consolidated all the thinking together before moving on to look at ratios and fractions.

We know that 1:7 is comparing 1 to 7, and we can write it as a fraction 1/7. We can also say that 1 and 7 are both parts, so the whole would be 8, and we can make fractions of 1/8 and 7/8 as well. This is helpful when we are solving ratio problems.

The question we had next was to make a bag of trail mix that is in a ratio of 2:3:4 sunflower seeds: raisins: peanuts. If we want 600 grams total how many grams of each ingredient do we need to mix?

It was great to see their different ways of presenting their work to show their understanding, and how they verified their work to check that it made sense and was reasonable.