Why did I write these numbers this way?
The idea is that the product of the digits of the numbers are equal to the number of letters in the number itself:
137: $1 \times 3 \times 7 = 21$ "One hundred thirty seven" has 21 letters (ignoring spaces)
225: $2 \times 2 \times 5 = 20$ "Two hundred twenty five" has 20 letters
317: $3 \times 1 \times 4 = 21$ "Three hundred seventeen" has 21 letters
Now the side questions:
What are the next two numbers with same shared property?
522 and 613
What are the previous two with the same shared property?
91 and 42 (obviously 42, duh!)
What is the largest three digit number with the same property?
731
What is the smallest two digit number with the same property?
18, 25
Bonus:
You missed one between 137 and 225.... it's 219.
Explanation:
I cheated obviously..
I found this website (https://lingojam.com/NumbersToWords) that transforms numbers into words.
Then I wrote this js code in the browser console using their js function inEnglish
which is the one called when you type something in the wensite
for (var i = 11; i< 1000; i++) {
var str = inEnglish(i).replace(/\s/g, '').replace('-', '').length;
var prod = 1;
var stringIndex = i.toString();
for (j = 0;j<stringIndex.length;j++) {
prod *= parseInt(stringIndex[j]);
}
if (prod === str) {
console.log(i);
}
}
.
The output was all the numbers with this property from 11 to 999
18,25,42,91,137,219,225,317,522,613,731
I started from 11 because 10 results in a digit product of 0 and it makes no sense.
For Daniel Mathias... 1 digit numbers
4.... that's it.