How many times did Anna Himes use her Mastercard when paying between 12/25/2014 and 5/20/2016 ?
Mastercard refers to CreditCardType = 'MasterCard'; between 12/25/2014 and 5/20/2016 refers to TransactionDate BETWEEN '2014-12-25' AND '2016-05-20';
SELECT COUNT(T2.CustomerID) FROM customers AS T1 INNER JOIN `transaction` AS T2 ON T1.CustomerID = T2.CustomerID WHERE T1.First = 'Anna' AND T1.Last = 'Himes' AND T2.CreditCardType = 'MasterCard' AND T2.TransactionDate BETWEEN '2014-12-25' AND '2016-05-20'