Arithmetic Operators

Part of the First Circuits section of Coddy's Arduino journey. Lesson 14 of 22.

C++ has five arithmetic operators:

+ adds and - subtracts
* multiplies
/ divides
% gives the remainder of a division: 17 % 5 is 2, because 17 is three 5s with 2 left over

They work on numbers and on variables. As in school maths, *, / and % go before + and -, and parentheses go first of all:

int a = 2 + 3 * 4;    // 14: the 3 * 4 first
int b = (2 + 3) * 4;  // 20: the parentheses first

With two whole numbers, / gives a whole number: 20 / 6 is 3. The next lesson explains why.

Challenge

Easy

The starter has int a = 20; and int b = 6;. In setup(), print each of these on its own line, in this order:

A label before an answer on the same line, like a + b = , is fine. Press Run, then Check.

Try it yourself

int a = 20;
int b = 6;

void setup() {
  Serial.begin(9600);
  // print the six answers, one per line
}

void loop() {
}

Test yourself

This lesson includes a short quiz. Start the lesson to answer it and track your progress.

All lessons in First Circuits

1Hello, Board

4Decisions

2Talking to Your Computer

3Math on the Board

Practice on your own: Arduino playground