Teach Your Kids Arithmetic - Fractions, Percents, and Decimals

Admittedly fractions are trouble for mostare manhole covers round?", which I presented in
students. In my previous article I talked aboutmy article Why Study Math - The Circle
why this is so. Percents and decimals too presentFor those educators reading this, they know that
their share of problems to young students-adultsa common rebuttal of the math student is "When
as well. There is an interesting connectionam I ever going to use this?" In fact, a common
between these three mathematical entities andgripe I would hear is "This is totally useless stuff."
here it is: fractions, percents, and decimals areIn preparation for these questions, I worked
variations of one and the same thing.diligently so that I could show students that there
That is correct! These three curious mathematicalactually was a connection-a reason-why they
objects, which go parading around as though theywere studying the particular lesson at hand.
had independent identities, are really one and theFor the topic in question-fractions, percents, and
same. It's like Clark Kent and Superman: you takedecimals-students must be made aware that a
off the glasses and suit, and you get Superman.fraction is a percent and that a percent is a
Learn about the personality of one, and you'vedecimal. Once students know that they are
mastered the intricacies of the other.dealing with one and the same thing, and not
When I pointed this relationship out during one ofthree separate ones, they feel less overwhelmed
my lessons, one student looked at me infrom having to know all about percents, all about
amazement and said that he never realized that.fractions, and all about decimals. When students
This boy had gone through school for twelvenow see 1/8, they know that this is a
years-he was a senior in high school-and nevermathematical synonym for 12.5% or 0.125.
saw that connection. When I would stress thisSimilarly 1/4 is 0.25 which is 25%; 3/8 is 37.5% or
relationship throughout my different classes, I0.375; ½ is 50% or 0.5; 5/8 is 62.5% or
would get similar reactions from many students:0.625 and 3/4 is 75% or 0.75.
they just never made the connection that linkedAs obvious as the previous mathematical
these three seemingly different ways ofsynonyms are to those who understand them,
expressing a mathematical idea.these relationships elude many students, and they
Now this is a problem with mathematics educationend up in ignorance, much like the senior of mine
in this country. Connections are not madementioned earlier-and this can be a life-long
between topics in this difficult discipline. For thisignorance, unfortunately. Yet once connections like
reason, students are left scratching their headsthat among fractions, percents, and decimals are
wondering when in the world they will ever usemade, connections and cross links are made in
something like a decimal, a fraction, or a percent,other areas as well. When this is done,
even though these basic things are literallymathematics is no longer the formidable bugbear
encountered everyday. This failure to connectthat many take it to be.
math to reality harks back to questions like "Why