Use measuring cups to show equivalence. Measure 2/3 cup of water. Give your child the water and a 1/3 -cup measuring cup. Ask him how many times he will be able to fill the 1/3-cup measuring cup with the water. Prompt him to prove it and then to say the decomposition in a number sentence, first using addition and then using multiplication (e.g., 2/3, = 1/3 + 1/3 and 2/3 = 2 x 1/3).
Play Fraction Number Battle with fractions less than 1, and with fractions greater than 1.
Together, find one of your child’s favorite recipes. Look at the amount needed for each ingredient. Pose the following questions: What happens if we want to make two batches of the recipe instead of one? How much of each ingredient will we need?
May-June: On index cards or small pieces of paper, write each of the fractions, in tenths, from 1/10 to 10/10 (i.e. 1/10, 2/10, 3/10 … 10/10). On another set of index cards, write each of the decimal numbers, in tenths, from 0 to 1.0 (i.e., 0.1, 0.2, 0.3, ... , 1.0). Create a game using the cards. For example, play a memory game to create matches of equivalent amounts (e.g., 1/10 and 0.1). The person with the most matches wins. For a challenge, change the objective to creating matches of pairs that add up to one (e.g., 1/10 and 9/10 or 0.2 and 8/10 ).
Although it may be tempting to show your child how to add numbers in decimal form by lining up the decimals, it will be more helpful to support the current lesson of adding decimals by converting to fractions. The objective is for students to see that writing numbers in decimal form is just another way of expressing whole numbers, tenths, and hundredths that were written in fraction form (e.g., 86/100 = 0.86 ). In other words, the decimal and fraction forms share the same point on the number line. Students will be taught to add numbers in decimal form by lining up the decimals in Grade 5 of Eureka Math.