Prepare students to understand the concept of fractions and decimals by talking about language. For example, the words "cat" and "feline" mean the same thing. Ask the students for other examples of synonyms that they commonly use. Show that math also uses synonyms. Talk about the different ways of expressing the same idea. Fractions, decimals and even percentages are different ways of showing parts of a whole. Use songs or poems to help students remember the basic concepts of decimals and fractions.
Fractions and decimals are part of counting money. Pass out different paper dollars and plastic coins to each student. Ask the students to name the quarter, dime, nickel and penny. Talk about how much each coin is worth. Ask the students to write out the coin amount as a decimal. For example, two dollars and a quarter is the same as 2.25. Show the students that dollar amounts are decimal expressions. Ask the students how many quarters equal a dollar. Talk about how one quarter or 1/4 is a fraction. Explore other fractions such as 1/10, 1/20 or 1/100.
Give each child a set of base 10 blocks. These cubes fit together. Students can fit 10 blocks together to make a rod and place 10 rods together to make a block of 100 cubes. Show the students that the block is one single unit. Different parts are a portion or a fraction of one whole block. Remove 50 blocks. Show the students that it can be expressed as 50/100. Show that there are two ways to express 50/100. The fraction can be simplified to 1/2, or you can divide 50 by 100 and get 0.50 or 0.5. It is important that students understand that 1/2, 0.5 and 50/100 are all the same thing. Practice with other fractions of the entire 100-cube block.
Once students have grasped the idea of decimals and fractions, they need to practice changing from fractions to decimals and back. Traditionally, handout sheets or workbooks gave students this practice. However, today there is a wide range of free and low cost computer games that give students a fun way to practice these new math skills. Students convert fractions to decimals or percentages as part of larger role playing or action games.