Grade Level: 3-5
Skills: fractions, adding fractions, using measures, mixing colors
Measuring cups marked off in 1/2, 1/4 and 1/3 gradations
Water and food coloring
Bucket to collect water
In this activity, students will mix fractional amounts of colored water to make new colors. Be prepared for fun and mess!
Intro: Discuss the gradations on the measuring cups.
What relationships, if any do they see? Ask:
How many thirds in 1 cup?
How many halves in 1 cup?
How many quarters in 1 cup?
How many quarters in a 1/2 cup
Ask: How many 1/2 cups are needed to make 1 full cup?
Pour red water into two measuring cups until each one is 1/2 cup full.
Pour both 1/2 cups into one empty cup to check
Ask: How many 1/2 cups would you need to make 2 whole cups of water? (4)
Demonstration Part 2: Again, fill two measuring cups with a 1/2 cup of red water. Pour blue water into a third measuring cup until it is 1/2 full of blue water.
How many halves are there now? (3)
Ask: What fraction of the halves are blue? this will force students to change gears and look at the fact that they are discussing parts of the set of 3 now. (1/3 are blue)
Ask: What fraction of the halves are red? (2/3 are red)
Demonstration Part 3:
How much water, and what color will be created when 1/2 cup of red water is poured into the 1/2 cup of blue water?
Students use measuring cups and colored water to invent new colors and record them on the invent-a-color worksheet.
Fill 1 cup 1/2 full of red water.
Fill another cup 1/4 full of blue water.
Compare the amount of water in the blue and red cups.
Which is a greater amount 1/4 or 1/2?
How many quarters are in 1/2?
What is 1/4 + 1/4 equal to?
How many quarters are needed to fill 1/2 cup?
How many quarters are needed to fill 1 cup?
How many quarters are needed to fill 2 cups?How much water will be there in all if 1/4 cup is poured into 1/2 cup?
If a cup is 1/4 full:
How many more quarters are needed to make 1 cup?
What is 1/4 + 3/4?
What color do you think you will get if you pour 1/4 cup of the blue water into 1/2 cup of the red water?