General Math On-line
Chapter 2 Decimals Overview
What will I be able to do when I finish this chapter?
Write appropriate decimals from given information.
Convert between fractions and decimals.
Compare decimals
Round and truncate decimals to required place value.
Select the appropriate operation ( + - x ¸ ) to solve a problem.
Add and subtract decimals.
Multiply and divide decimals.
Solve application problems.
Chapter 2 Tips and Hints:
Decimals are like fractions. They help you express a number that is less than a whole. For example, if you have 2 dollars and 3 quarters, you have more than 2 dollars but less than 3 dollars. You could express this amount as a decimal by saying 2.75 dollars.
The decimal point in a number (such as $2.75) separates the whole number on the left from the part on the right. (2 whole dollars and 75/100 of another dollar)
The place where a digit is located makes a big difference in determining the value of the number.
3.000 = is 3 whole things
0.300 = is 3 tenths = 3/10 = 3 parts out of 10
0.030 = is 3 hundredths = 3/100 = 3 parts out of 100
0.003 = is 3 thousandths = 3/1000 = 3 parts out of 1000
To make sure your answers are as accurate as possible, don't round any intermediate results. In other words, don't round until you get to your final answer.
Simplify the problem to help you decide what needs to be done. If you don't know how to approach a problem that has decimals, replace the decimals with whole numbers.
If you were preparing a meal for 35 people and each person was to receive 0.75 pounds of steak, how many pounds of steak would you have to buy?
If this problem looks too complex, simplify it by replacing the decimal with a whole number. If every person were to receive 2 pounds of steak, you would have to buy 70 pounds of steak. You multiplied to get the answer. If multiplication works with whole numbers then it will work with decimals as well. You will have to multiply 35 by 0.75 to get the answer.