Decimals are used every day; they are seen at the cash register at your store, your bank statement, and even online. But if you reach deep into the recesses of your mind you might remember the math and science classes and all the decimals used that have nothing to do with dollars and cents. If you’ve scratched your head at all the pie jokes on Facebook every March 14, you are not alone. I have the advantage of having gone back to college in my 30s to have brushed up on decimals, how they are used, and when to use them. A decimal place value chart can assist you in your endeavors to not look ignorant when you have to read them aloud in a group presentation.
What Is a Decimal?
A decimal is a way to display the value of a number that is not a whole number. Decimals, fractions, and percentages are all related and are different ways to look at partial numbers.
Say you decide to make a sandwich; make it roast beef with horseradish, Gouda, arugula, and roasted red peppers on crusty French bread, and it’s a big sandwich (sorry if I made you hungry, I’m a trained chef). You have three friends that walk into the room, one with a bag of chips, one with a bottle of Coke, and another with Klondike bars. “We’ll share if you do”, the friend with the Coke says, and you agree. So you make three cuts into the sandwich with your bread knife. You grab four plates and the dividing happens. You are now sitting there with 1/4 of the sandwich, chips, Coke, and ice-cream. You could say that you have 25% of the food, or you could say that you have 0.25 of the food.
Now in everyday life, we would be unlikely to use the decimal to describe this division, and much more likely to use the fraction or percentage. But when it comes to more complex figures with more digits, such as those used in chemistry, we are more likely to use the universal language of decimals.
Decimals seem more scientific, yet you use them every day with money, and you almost always use the decimal to describe dollars and cents, so this is just a step further down the understanding. First you need to understand place value.
What Is Place Value?
Place value is simply as positional notation system. The value of each number is determined by its position. The value of each digit is based on the number 10 because the decimal system is a base ten system. The position in a decimal number is given a power of 10.
- 100=1, or ten to the power of zero equals one
- 101=10, or ten to the power of one equals ten
- 102=100, or ten to the power of two equals one hundred
- 103=1,000, or ten to the power of three equals one-thousand
It works the same with negative exponents too.
- 10-1=1/10, or ten to the power of negative one equals one-tenth
- 10-2=1/100, or ten to the power of negative two equals one-one hundredth
- 10-3=1/1000, or ten to the power of negative three equals one-one thousandth
That’s not so hard to understand. To make it even easier you can use a decimal place value chart.
What Is a Decimal Place Value Chart?
A decimal place value chart is a tool you can use to help you learn to read and write decimals. If you have difficulty understanding place value, these charts can be a valuable tool. Many people tend to forget to use place holder 0’s or simply use too many. For instance, 347 might be incorrectly written as 30407. You can use these charts to add and subtract as well.
It is actually a table by definition. To make one, you can use the table feature in Word or any other word processing program. But we will call it a chart as that is the conventional name given to this element.
Examples of Decimal Place Value Charts
Decimal place value charts do not have a prescribed look, although they always the same in placement. They can grow giving room for more placement of value giving room for millions, millionths, billions, billionths, and beyond. Below, I have created an example for you:
In image 1 below, notice that before the decimal point, the terms end in the plural s. But after the decimal point, they end in ths. This is very important to remember thousands is whole numbers, thousandths is a decimal term.
The number is 3,684.26 or three thousand, eighty-four and twenty-six hundredths.
Hey math whizzes!
Now for a challenge: try to enter Pi, with some of the decimal digits, into a chart and read it.
Hint: try using Excel to make the chart.
If you try it post a reply below, and tell me what you get. How far can you get?