There are two Khan Academy videos on representing numbers as decimals, percents, and fractions. This one shows students how to represent a fraction as a decimal and a percent. Sal demonstrates the process used to convert the fraction 7/8 into a decimal and then a percent. This presentation is very well done and would be great at an independent work station or as homework support.
Clear up the confusion and help your learners make the connection between percents, decimals and fractions. This video describes the process needed to write 18%  first as a decimal, and then as a fraction in its simplest form. Sal does a succinct job of explaining these concepts.
Having a good number sense is key to understanding place value. This video clearly explains the place values that comprise a decimal number. It is a very straight forward presentation and would be appropriate for grades 3, 4, or 5. Sal uses multiple colors and expanded notation to describe the value of each number.
Decimals are quite often confusing for young mathematicians. Pupils engage in three activities: writing decimal names, understanding place value, and comparing decimals to thousandths. At the end of the lesson, there is a motivating game called beat the clock which will test your students' ability to correctly write decimals. A terrific lesson which should help your mathematicians gain confidence in this important area of math.
Here is a fabulous lesson on subtracting decimals with different numbers of decimal places. There are teacher-led activities for learners to engage in, including, modeling decimal subtraction through decimal squares, looking at place value, seeing patterns in decimal numbers, and finding decimal values on a number line. Then, pupils pair off and play an interactive online game that further reinforces the concepts being taught. Finally, each pupil completes a series of worksheets that are embedded in the plan to gain further practice. An outstanding math lesson plan which should lead to meaningful learning.
Mr. Khan reminds us that the most important thing to remember when subtracting decimal numbers is to line up the decimal points. He subtracts 3.600 from 9.005, explaining his thinking as he completes the process. Assign the viewing of this tutorial as homework and then have youngsters come to class ready to practice together!
Trying to get your class to think of decimals as fractions and vice versa can lead to interesting discussions. After all, we can usually understand quickly that 1/4 is .25 but why is 1/7 not so easy to convert? This activity looks at these problems and tries to draw conclusions about why certain numbers are easier to work with mentally, leading to interesting insights into our number system and powers of ten. 
In a writing prompt, learners are asked to check the calculation of a decimal exponent without a calculator. Use as an opener or assessment after studying fractional exponents. Requires a strong understanding of exponents and roots to accurately answer the problem.
Divide decimals. Watch as Sal explains how to divide 1.03075 by 0.25. He provides a step-by-step process that is easy to follow, clear, and well-organized. Note: This would be great for a teacher prepping for a math lesson or as supplemental material to show in class.
Have your young mathematicians complete this practice problem along with Sal. To solve this thinking problem, they will need to multiply decimal numbers in order to determine the cost of 14.6 gallons of gas when gas costs $2.70 per gallon.
Adding decimal numbers is very similar to adding whole numbers. Sal takes you through the process in this video. First he lines up the decimal points. Then he adds each place value, regrouping when necessary.
A rational number is a ratio of two integers. Discuss with your class how to convert the rational numbers of repeating decimals to fractions. A good commentary on letting x equal the repeating decimal and multiplying each side of such equation by a power of 10 or 10r, where r is the repeating segment.
By using visual aids, and explaining mathematical language students can get a concrete grasp of how to multiply decimals.
Students can learn how to convert percents to decimals and fractions using 10x10 grids.
Learners insert the comparison symbols between numbers containing decimals. Answers are not provided.
Review estimation of decimals and fractions, then estimate which is bigger. Middle schoolers will order fraction and decimals, practice finding equivalent fractions, and their equivalent decimals. The lesson includes a total of 10 related worksheets!
Fourth graders engage in a instructional activity that is about the concept of rounding decimals. They review place value and focus it upon the practice of rounding. Students use 10 base decimal grids or models to help make connections with the skill.
For this fractions and decimals worksheet, 4th graders use a calculator to change 9 proper fractions into their equivalent decimals and then solve 2 word problems about fractional values of money.
Here is a 42-question quiz dealing with decimals to the thousandths place. It is comprehensive in that it has test takers use inequality signs to compare pairs of decimal numbers, choose the least- or greatest-valued nubmer out of a set of five, and then identify a number described in expanded form. 
Students identify and write the decimal and fraction represented in a given model. For this fractions and decimals  lesson, students write the numerical equivalent in decimal and fraction form after observing the teacher create a model with various manipulatives. Students complete a related chart.