Factfulness: Ten Reasons We're Wrong About the World – and Why Things Are Better Than You Think

Divide the Numbers
Often the best thing we can do to make a large number more meaningful is to
divide it by a total. In my work, often that total is the total population. When
we divide an amount (say, the number of children in Hong Kong) by another
amount (say, the number of schools in Hong Kong), we get a rate (children
per school in Hong Kong). Amounts are easier to find because they are easier
to produce. Somebody just needs to count something. But rates are often more
meaningful.
The Trend Below the Division Line

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I want to return to the 4.2 million dead infants. Earlier in the chapter we
compared 4.2 million babies to the 14.4 million who died in 1950. What if
fewer children are being born every year and that’s the reason fewer babies
are dying? When you see one number falling it is sometimes actually because
some other background number is falling. To check, we need to divide the
total number of child deaths by the total number of births.
In 1950, 97 million children were born and 14.4 million children died. To
get the child mortality rate, we divide the number of deaths (14.4 million) by
the number of births (97 million). That comes out to 15 percent. So in 1950,
out of every 100 babies who were born, 15 died before their first birthday.
Now let’s look at the most recent numbers. In 2016, 141 million children
were born and 4.2 million died. Dividing the number of births by the number
of deaths comes out to just 3 percent. Out of every 100 babies born across the
world, only three die before reaching the age of one. Wow! The infant
mortality rate has changed from 15 percent to 3 percent. When we compare
rates, rather than amounts of dead children, the most recent number suddenly
seems astonishingly low.
Some people feel ashamed when doing this kind of math with human lives.
I feel ashamed when not doing it. A lonely number always makes me
suspicious that I will misinterpret it. A number that I have compared and
divided can instead fill me with hope.