David got $14/hour x 2 hours/day = $<<14*2=28>>28 per day from mowing.
So in a week, he had $28/day x 7 days = $196.
A pair of shoes cost $196/2 = $<<196/2=98>>98.
David gave his mom $98/2 = $<<98/2=49>>49.
The total amount he spent and gave is $98 + $49 = $<<98+49=147>>147.
David is left with $196 - $147 = $<<196-147=49>>49.
#### 49