Do math in the terminal!

math.sh

# add this in ~/.zshrc

math() {
	local MATH_RESPONSE
	case $(($RANDOM % 3)) in
		0)
			local MATH_A=$(($RANDOM % 10000))
			local MATH_B=$(($RANDOM % 10000))
			read "MATH_RESPONSE?$MATH_A + $MATH_B = "
			local MATH_ANSWER=$(($MATH_A + $MATH_B))
			;;
		1)
			local MATH_A=$(($RANDOM % 100))
			local MATH_B=$(($RANDOM % 100))
			read "MATH_RESPONSE?$MATH_A * $MATH_B = "
			local MATH_ANSWER=$(($MATH_A * $MATH_B))
			;;
		2)
			local MATH_NUMBER=$(($RANDOM % 500 + 1))
			read "MATH_RESPONSE?The prime divisors of $MATH_NUMBER are (from small to big, separated by a single space) "
			local FACTORRESULT=$(factor $MATH_NUMBER)
			local MATH_ANSWER=${FACTORRESULT#$MATH_NUMBER: }
			;;
	esac
	if [ "$MATH_RESPONSE" != "$MATH_ANSWER" ]; then
		cowsay "The answer is $MATH_ANSWER"
		false
	else
		true
	fi
}

domath() {
	local MATH_SCORE=0
	while do
		local MATH_START_TIME=$(\date +%s%N)
		math
		if [[ $? != 0 ]] then
			printf "Score: %.3lf\n" $MATH_SCORE
			if [[ $MATH_HIGHEST_FILE_PATH == '' ]]; then
				MATH_HIGHEST_FILE_PATH="$HOME/.math_highest_score"
			fi
			MATH_HIGHEST=$(( $(\cat "$MATH_HIGHEST_FILE_PATH") ))
			if [[ $MATH_SCORE -gt MATH_HIGHEST ]]; then
				echo "New highest score!!!"
				echo $MATH_SCORE > "$MATH_HIGHEST_FILE_PATH"
			fi
			break
		else
			MATH_SCORE=$(($MATH_SCORE + 10000000000.0 / $(($(\date +%s%N) - $MATH_START_TIME + 1000000000)) ))
		fi
	done
}