Math teachers have the challenging job of taking abstract concepts, such as ratios, and simplifying the ideas so that a student can understand and be able to apply it to his life. The best way to teach ratios so that students can understand the concepts is by including a manipulative or tangible object in the lesson plan. A practical fifth grade math lesson on ratios can be taught using M&M's.
Teach the students that a ratio is a comparison of two things and that there are three ways to write ratios: as a fraction, with the word "to" and with a colon.
Hold up the bag of M&M's and tell the students that you know exactly how many M&M's there are, plus the amount of green, blue, red, etc.
Write down the name of each colour moving vertically down the board, and the amount next to it. So for green, you would write green = 12 and underneath that you would write blue = 10. Make sure to line up each set of words and numbers, one above the other so that the students can view it clearly.
Compare two colours to one another making a ratio. If you compare the number of blue M&M's (10) to the number of green M&M's (12), you get 10/12 or 10 to 12 or 10:12.
Give every two students a bag of M&M's and paper. Tell the students to count each colour separately, and make a list of the colours and numbers, just as you did on the board.
Tell the students to number the papers 1-5 and pick four colours and write ratios. Each ratio should be written down three different ways.