On the Subject of Number Cruncher

Modules made by GS Electronics & Co.™ were slightly smaller in the year after their founding, compared to their modules afterwards. That’s because there were no standards in place for the relative sizes and functions of bomb components, and you were just expected to know which modules would fit on what casing, et cetera. While this specific line of modules was discontinued after IBM (International Bomb Maintenance) set their standards, you can still occasionally find them on bombs to this day, but getting them to fit on modern bombs takes some artistic licence.

At the top-right of this repurposed cash register is a segment of tape displaying a number — this is your current score. The module will solve when your score reaches at least 20.

If the required number of points has been changed in this module’s mod settings, the gears behind the module will not turn.

To earn points, you need to perform operations on 12-digit numbers. The tape at the top-left will show a symbol and the LCDs in the middle will either show one 12-digit number, or two. Use the operator represented by the symbol on the number(s) and type the result using the keypad. Your input will appear on the bottom LCD. To delete the rightmost digit, press DELETE; to submit, press the dollar sign.

• If your answer is correct, the number of points associated with the current operation will be added to your score, and a new operation and number(s) will be displayed. The number of points that each operation will award is listed beside it in the table on the next page.
• Otherwise, the module will strike and briefly display which digits were incorrect. This will not clear your input.

The HELP button between the two reels of tape will play a transcript of the current operation, from the table overleaf. You can stop this recording by pressing the button again. (It was recorded by an unpaid apprentice, if that matters.)

Keyboard Support

This module has keyboard support, meaning that you can use your keyboard to type & submit answers. You can type digits using the number keys / number pad, submit with the return key and delete a digit with backspace.

List of Operations

Symbol	Name	Score	Calculation Process
	Altitude	7	For each digit, type the last digit of the number of digits it is greater than.
	Attendance	4	For each digit, type the last digit of the number of times it appears in the number.
	Determinants	7	For each of the six 2×2 grids of digits, type the absolute value of (A × D) - (B × C), where A - D are the digits in reading order. Prepend 0’s if necessary.
	Difference	4	For each pair of digits, type their difference.
	Equality	2	Type the number exactly.
	Exclusive OR	4	For each pair of digits, type their sum, modulo 2.
	Inverse	4	Type 9 minus each digit.
	Lovers	5	For each pair of digits, type their Manhattan distance from each other, on the module’s keypad.
	Lunar Logic	4	For each pair of digits, type the highest.

continued on next page...

List of Operations (cont.)

Symbol	Name	Score	Calculation Process
	Magnitude	1	For each digit, if it is 5 or greater, type 1, else type 0.
	Maximum Digit	2	For each digit, if it is greater than all of its neighbours, type 1, else type 0.
	Means	4	For each pair of digits, type their mean, ignoring decimals. The mean of two numbers is their sum, divided by 2.
	Modulo	4	For each pair of digits, type the remainder of the first divided by the second. Treat 0’s in both numbers as 10’s.
	Neighbour Sum	6	For each digit, type the last digit of the sum of its neighbours and itself.
	Numeric Weight	7	For each pair of digits, type the combined number of ones in their binary representations.
	Pair Differences	5	For each of the six pairs of two-digit numbers in both numbers, type their difference, prepending 0’s if necessary.
	Pair Products	4	For each of the six pairs of digits, type their product, prepending 0’s if necessary.
	Parity	1	Type each digit, modulo 2.

continued on next page...

List of Operations (cont.)

Symbol	Name	Score	Calculation Process
	Plus One	7	For each digit, add the number of digits to its left and type the last digit of the result.
	Prime Checker	4	For each pair of digits, if their sum is prime, type 1, else type 0.
	Product	5	For each pair of digits, type the last digit of their product.
	Reversal	2	Type the number in reverse.
	Sorting	4	Sort the digits of the number from 0 to 9.
	Sum	4	To find digit N of the answer, take the last digit of the sum of the first N digits.
	Thermometer	2	Start with a 1. Then, for each digit that isn’t the first, if it is greater than the digit to its left, type 1, else type 0.
	Trickster	5	For each digit in the first number, find its next occurrence, wrapping around if necessary, then type the digit below it.
	Triplity	2	Type each digit, modulo 3.

continued on next page...

List of Operations (cont.)

Symbol	Name	Score	Calculation Process
	War	3	Concatenate both numbers. Then, for each of the twelve pairs of digits, type 0 if the first number is larger than the second, 1 if the second number is larger than the first, and 2 otherwise.
	X-Sum	7	For each digit N, type the last digit of the sum of the first N digits in the number. The sum of 0 digits is 0.