Lena had $$86$$ strawberries. She gave away $$29$$ strawberries to her brother. After her mother gave her some strawberries, she had $100$ strawberries. How many strawberries did her mother gave her? Her mother gave her~\uline{~~~~~~~~~~}~strawberries. 
Overseas Competition->Knowledge Point->Word Problem Modules->Applying Addition and Subtraction->Simple Addition and Subtraction