See if you can figure out what the rules are that make these math statements true:
3 + 2 = 15
6 + 5 = 111
9 + 2 = 711
8 + 4 = 412
5 + 2 = 37
7 + 6 = 113
9 + 8 = 117
15 + 3 = 1218
If you’re right, you should be able to answer these:
20 + 9 = ?
? + ? = 317
Scroll down for the answer …
A little more …
20 + 9 = 1129
and
10 + 7 = 317
In each of the examples, the rule is that the number on the right-hand side of the = sign has two components. The first is formed by finding the difference between the two numbers on the left of the equation. Then add the two numbers and write their sum next.
Thus, the difference between 20 and 9 is 11.
Adding 20 + 9 gives us 29.
When we write them together, that gives us 1129.
Treat 317 as two pieces. The difference between the two numbers must be 3 and together they add up to 17. 10 + 7.