# 4.NF 5: Coins & Dollars & Decimals, O My! (#267)

A Year in the Life: Ambient Math Wins the Race to the Top!
Day 267

For one year, 365 days, this blog will address the Common Core Standards from the perspective of creating an alternate, ambient learning environment for math. Ambient is defined as “existing or present on all sides, an all-encompassing atmosphere.”

And ambient music is defined as: “Quiet and relaxing with melodies that repeat many times.” Why ambient? A math teaching style that’s whole and all encompassing, with themes that repeat many times through the years, is most likely to be effective and successful. The CCSS math standards are listed here in blue followed by their ambient counterparts.

Number and Operations – Fractions 4.NF
Understand decimal notation for fractions and compare decimal fractions.
5. Express a fraction with denominator 10 as an equivalent fraction with denominator 100, and use this technique to add two fractions with respective denominators 10 and 100.  For example, express 3/10 as 30/100, and add 3/10 + 4/100 = 34/100.

Math By Hand covers this standard nicely with two modalities:
1) Coin rubbings or copies that show decimal/fraction conversion and equivalency, as well as reductions of both fractions and decimals from 100ths to 10ths.  For coin rubbings: scatter quarters, dimes, nickels, and pennies on a tabletop, cover with newsprint, lightly tape the corners, and rub with the broad end of a black crayon.  For coin copies: scatter the same configuration on a copy machine glass and copy.  Proceed as shown below.

2) The Decimal Strip: A felt strip and numbered index cards represents both coin and dollar amounts, and translates these into decimal 10s and 100s.  The top image is an excerpt from the Grade 4 binder and the bottom image is the felt strip itself with numbered index cards and quarters.

With these and other tools and plenty of skills practice, decimals are a cinch.  Having the basics of fractions and decimals on hand builds the kind of confidence needed to follow that Grade 4 need for adventure and exploring: today the neighborhood, tomorrow the world!  Here is a Grade 5 chalkboard drawing from Catie Johnson (not meant to be a globe but rather a depiction of the North American continent).  See her gallery of chalkboard drawings here.

Knowledge ensues in an environment dedicated to imaginative, creative knowing, where student and teacher alike surrender to the ensuing of knowledge as a worthy goal. Tune in tomorrow for more Grade 4 math CCSS and their ambient counterparts.