Depending on how you arrange the letters on the blocks, you can spell 16 words:
All these words are made using seven blocks (depending on the word). So, the blocks you are not using you can just store a few and then when you feel like changing the word in your house simply just rearrange the blocks to spell a new word.
Each block has the following letters:
Block 1- f, b, t, w
Block 2-m,e,d,oBlock 3- c,s,a,r
Block 4- e,p,t,rBlock 5- n,l,v,o
Block 6- s,i,m,kBlock 7- y,e,h,d