In this Cyberchase interactive game, Hacker has removed some of the tracks on the Trans-Cyberspace Railroad. The challenge is to repair the tracks so that the Cybertrain can get back to the central station. A set of spare tracks that range in length from 0.1 to 1.0 will be used to fill in the gaps. In many cases it will be necessary to use a combination of two or three pieces to fill in the missing part of the track. All the gaps on the screen must be filled before the train will move.
You can describe many quantities with a whole number—the number of students in a classroom, the number of soda cans sold at lunch, the number of tennis balls you own. But other quantities cannot be described using a whole number—such as the number of inches a person grew last year or the amount of money in your wallet. When you need to describe a part of the whole, you must use fractions and decimals.
Fractions use the idea of sharing or dividing, while decimals extend the place value system to include tenths, hundredths, thousandths, and so on. You can write a quantity in either fractional or decimal notation, but the situation may require one form rather than the other. We commonly use fractions to describe measurements in construction and cooking. We commonly use decimals in financial applications, in scientific measurements and distance, and when using a standard calculator.
Decimals allow you to describe quantities smaller than one, and they allow you to combine these quantities with whole numbers. For example, instead of saying "three plus one-half," we can write 3.5. Decimals also allow for a more precise measurement in many cases since they extend the place value system to the level of accuracy you can measure.
When adding or subtracting decimals it is important to consider the precision, or the number of decimal places each number has. By lining up the decimal points before completing the addition, you can be certain that you are combining the correct values. In some cases, it is appropriate to round numbers to the nearest tenth or hundredth in order for all numbers to have the same level of precision. Your combined value can only be as precise as the least precise measurement in the set of numbers.
Academic standards correlations on Teachers' Domain use the Achievement Standards Network (ASN) database of state and national standards, provided to NSDL projects courtesy of JES & Co.
We assign reference terms to each statement within a standards document and to each media resource, and correlations are based upon matches of these terms for a given grade band. If a particular standards document of interest to you is not displayed yet, it most likely has not yet been processed by ASN or by Teachers' Domain. We will be adding social studies and arts correlations over the coming year, and also will be increasing the specificity of alignment.