maths question solving

Today my maths group had to do a maths sheet called turn about.First we grab the work sheet then glued it into our maths book.Next we had to start with simple multiplication then we had to do the turn about questions.Finally I answered all the questions except the maths questions here are they there are 50 crackers in a pack and Mary bought 4 how many crackers does she have? the answer was 200 how I figured it out was I had 4 packets of crackers the I took away 2 packets then made them into 100 then I grabbed the other 2 then made them into 100 then I put 100 and 100 together and it made 200 the next and final question was there are 9 cookies in a pack Steve has 2 packs how many cookies does he have? the answer was 18 how I figured it out was I grabbed 17 then put it together with 1 and it makes 18.What I enjoyed was doing the question the easy way. What I might do differently next time is add a picture to show you the questions.