1. If it takes 1/3 to make a scarf then you can make 3 with one yard of fabric and since there are five you do 3 times 5 to make 15.
2. Since you want to build 8 and you can't use the wood you cut up already. All you need is eight because each board makes 1 birdhouse.
3. If there are 12 then you take 3/4 on all of them you get 12 but then you have some left over and then you get 4 more 3/4 which makes your answer 16.
4. If you un-simplify 3/4 you get 6/8 and half of 6/8 is 3/8 which is your answer.
