check cages

for(Ruleset rule : rules){

            if(!rule.hasEmptyCells()){


                switch(rule.getOperation()){
                    case '+' :
                        int sum = 0;

                        for(Cell c : rule.getCells()){
                            sum += c.getValue();
                        }


                        if(sum != rule.getTotal()){
                            return false;
                        }

                        break;

                    case '-' :

                        int difference = 0;
                        for(Cell c : rule.getCells()){
                            difference = Math.abs(difference - c.getValue());
                        }

                        if(difference != rule.getTotal()){
                            return false;
                        }

                        break;

                    case '*' :

                        int product = 1;
                        for(Cell c : rule.getCells()){
                            product *= c.getValue();
                        }

                        if(product != rule.getTotal()){
                            return false;
                        }

                        break;

                    case '/' :

                        float total = 1;
                        int temp = 0;
                        for(Cell c : rule.getCells()){
                             temp = c.getValue();
                            if(temp > total){
                                total = (float)temp/total;
                            }else if(temp < total){
                                total = total/temp;
                            }
                        }

                        if(total != rule.getTotal()){
                            return false;
                        }
                        break;


                }//close switch