On Children's Day, Xiao Ming went to the store and bought a box of flower balls and a box of white balls. The number of balls in the two boxes was equal. Due to the discount promotion in the program store, the price of the two kinds of balls is 5 for 2 yuan. As a result, Xiao Ming spent 4 yuan less, so how many balls did Xiao Ming buy in total?
"六一"儿童节，小明到商店买了一盒花球和一盒白球，两盒内的球的数量相等，花球原价1元钱2个，白球原价1元钱3个．因节目商店优惠促销，两种球的售价都是2元钱5个，结果小明少花了4元，那么小明共买了多少个球．
<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">4 / (2/5)</gadget>
<output>10</output>

<result>10</result>