By Ginna Royalty

## Chapter 1: The Language of Numbers

Journalists need to understand the importance of numbers so that they can be as accurate as possible. Numbers are everywhere, especially in newspapers. Always check the math and numbers in articles don’t assume that they are right. Make the numbers easier for readers: spell out single-digit numbers between zero and nine, round off numbers unless a specific number is required, do the math for your readers. Be careful with words like among/between, compared to/with, further/farther.

## Chapter 2: Percentages

Calculate percentages correctly so that readers can understand the material more effectively. The four common usages of percentages are percentage increase and decrease, the percentage of the whole and percentage points. Formula for percentage increase/decrease: Percentage inc./dec. = (new figure – old figure) ÷ old figure. Then convert to a percentage by moving the decimal over two places. The formula for percentage as a whole: percentage as a whole = subgroup ÷ whole group. Then move the decimal two places to the right. The formula for simple annual interest: Interest = principal x rate (as a decimal) x time (in years). The formula for payments on loans: A= monthly payment P= original loan amount R= interest rate N= the total number of months. A = [P x (1 + R)^{N } x R] ÷ [(1 + R)^{N} – 1]. The formula for interest on savings: B= balance after one-year P= principal R= interest rate T=number of times per year the interest is compounded. B = P(1 + [R ÷ T])^{T}

## Chapter 3: Statistics

After percentages, the most common numbers reporters work with are statistics. Statistics are used in research, crime rates, test scores and more. It is very common for journalists to be asked to evaluate surveys and studies. The mean is the sum of all figures in a group divided by the total number of figures. The median is the midpoint in the group of numbers. The mode is the number appearing most frequently in a distribution of numbers. Other categories of statistics include percentile, standard deviation, and probability.

## Chap 4: Federal Statistics

The federal government provides a lot of information involving numbers to the public, including unemployment rate, inflation, gross domestic product, international trade balance and more. The unemployment rate, which is defined by the percentage of the labor force that is unemployed and actively seeking work, is released every month. The formula is: unemployment rate = (unemployed ÷ labor force) x 100. Inflation is another big issue that journalists face. U.S inflation is measured by the Consumer Price Index.