If Both of them had 40 phone calls you would divide 40 phone calls to how much they actually had. In this case for Clara it's 40 divided by 10 which is 4, And then you have to multiply 4x4 which is 16. For Toby He had to divide 40 by 8 which is 5, and then multiply 3x5 which is 15. Therefore Clara had reached more phone calls then Toby.
Any time you have a subtraction and a negitive right next to eachother, it means to add. So, you would add 13 and 1 to get 14, then keep the denominator 19 to get 14/19.
12 People would be able to have 1 half kilogram of chocolate. In order to solve this problem you have to multiply 6 by 2. There are two halves in a whole. 6 times 2 is equal to 12.
