Operators

Package: ARITHMETIC_PACKAGE. Registered by createEngine(); for a slimmer engine, register it explicitly (see choosing packages).

An operator is the sign that joins two numbers into a sum: + to add, * to multiply, and so on. Solve reads the usual mathematical symbols, and it reads a word form for each, so a line can be written whichever way reads more naturally.

2 + 2 * 10 // 22
(2 + 3) * 4 // 20
10 - 4 // 6
20 / 4 // 5
2^10 // 1,024
17 mod 5 // 2

% is the percent operator, not modulo. Writing 17 % 5 is a parse error because 17 % is already a complete expression. Use mod or modulo.

^ is the only operator that groups from the right. A tower of powers is worked out from the top down, as in mathematics: 2^3^2 means 2^(3^2), which is 2^9. Everything else groups from the left, so 10-3-2 is (10-3)-2.

2^3^2 // 512
(2^3)^2 // 64

Operators in words

Most operators have a word form, which is often how a line reads more naturally.

8 times 9 // 72
2 plus 3 // 5
5 minus 3 // 2
10 divide by 2 // 5
3 multiplied by 4 // 12

with adds and without subtracts, which reads well for a running total.

40 with 2 // 42
40 without 2 // 38

Symbols pasted from elsewhere

A word processor, a chat client or a web page often replaces a typed hyphen with a minus sign (−) or an en dash (–), and the multiplication and division signs turn up in copied text and on some keyboards. Solve reads all four as the operator they look like, so a line pasted from a document still calculates.

10 − 3 // 7
10 – 3 // 7
3 × 4 // 12
12 ÷ 4 // 3

The em dash (—) is not an operator. It is a sentence mark, and a line that carries one is read as prose.