TYPO3 v7 has reached its end-of-life November 30th, 2018 and is not maintained by the community anymore. Looking for a stable version? Use the version switch on the top left.
There is no further ELTS support. It is recommended that you upgrade your project and use a supported version of TYPO3.
Sometimes a data type is set to "something +calc". "+calc" indicates that the value is calculated with "+-/*". Be aware that the operators have no "weight". The calculation is just done from left to right.
45 + 34 * 2 = 158 (which is the same as this in ordinary arithmetic: (45+34)*2=158)