Give the step-by-step reasoning process and then the final answer. Lara bought 52 stems of flowers at the flower shop. She gave 15 flowers to her mom and gave 6 more flowers than she gave to her mom to her grandma. She put the rest in a vase. How many stems of flowers did Lara put in the vase?
Lara gave 15 + 6 = 21 stems of flowers to her grandma. She gave away 21 + 15 = 36 stems of flowers. Therefore, Lara put 52 - 36 = 16 stems of flowers in the vase.
The final answer: 16.