Reading and writing whole numbers can be explained by using the following illustration. Take a close look and carefully study it!
Recall that the place value for 2, 4, and 6 are the hundred-thousands,the ten-thousands,and the thousands respectively.
Putting it all together, we have
(two hundred) thousand + (forty) thousand + (six) thousand
= (two hundred + forty + six) thousand
= (two hundred forty-six) thousand = 246 thousand
What gives us the right to just add two hundred, forty, and six?
Try to add the following:
two hundred cars + forty cars + six cars = ?
Would not you agree that it is equal to two hundred forty six cars?
The above is the same, except that instead of using cars, we are using thousand.
The group name, as shown in the illustration, is 'thousand'
In general, it is unnecessary to say the group name three times.
When reading whole numbers, always read the numeral first, which is 246 and then the group name from left to right.
Therefore, we read
(two hundred) thousand + (forty) thousand + (six) thousand as
(two hundred forty-six) thousand = 246 thousand.
By the same token, the next group name, which is 'millions' is read five hundred twenty million = 520 million
The whole number can be read as:
(two hundred thirty-four) billion (five hundred twenty) million (two hundred forty-six) thousand nine hundred seventy-eight
Notice the hyphen between seventy and eight. Similarly, 45 is written as forty-five with a hyphen between forty and five.
Finally, we need to include commas in the appropriate places, such as after "million" and "thousand"
234,520,246,978 = two hundred thirty-four billion, five hundred twenty million, two hundred forty-six thousand, nine hundred seventy-eight
Other examples