Mary had 6 lambs and 2 of the lambs had 2 babies each.  She traded 3 lambs for one goat.  One morning, she woke up and found an extra 7 lambs in the field.  How many lambs does Mary have?
2 of her lambs had 2 babies each so that adds 2*2 = 4 lambs
She starts with 6 and adds 4 baby lambs so she had 6+4 = 10 lambs
She traded 3 of those lambs for a goat so she has 10-3 =7 lambs
She has 7 and woke up to find 7 more lambs in the field so she has a total of 7+7 = 14 lambs