The number of sigma bonds in the above molecule is ___.

The carbon numbered $$1$$ has $$3$$ sigma bonds to hydrogen.

There is $$1$$ sigma bond between carbons $$1$$ and $$2$$.

The carbon numbered $$2$$ has $$1$$ sigma bond to hydrogen.

There is $$1$$ sigma bond between carbons $$2$$ and $$3$$.

The carbon numbered $$3$$ has $$1$$ sigma bond to hydrogen.

There is $$1$$ sigma bond between carbons $$3$$ and $$4$$.

There is $$1$$ sigma bond between carbons $$4$$ and $$5$$.

The carbon numbered $$5$$ has $$1$$ sigma bond to hydrogen.

$$\text{Total sigma bonds} = 3+1+1+1+1+1+1+1 = 10$$