1) An unknown number is doubled before adding eight . 2) Two is added to an unknown number and the result is multiplied by eight. 3) Seven is added to an unknown number. 4) A number is tripled before subtracting two, the result is divided by two before adding four. 5) An unknown number is subtracted from seven. 6) A number is multiplied by three and the result divided by two. Two is then subtracted before adding four. 7) An unknown number is tripled before subtracting two. The result is multiplied by three before adding four. 8) Two is subtracted from an unknown number and the result is tripled. Four is then added before multiplying by three. 9) A number is divided by thirteen before adding four. The result is then multiplied by three before adding four. 10) A number is multiplied by three before subtracting two. The result is then tripled and divided by thirteen just before the addition of four.