Prop: A poster board or newsprint pad on an easel, and a magic marker
When Kathy was in second grade, she had trouble understanding subtraction with numbers of two digits or more. For example, 56-17 (write on the pad as shown below).
How do you subtract seven from six when seven is the larger number? There isn't enough to subtract!
Dianne was Kathy's older sister. She was in fifth grade, and wanted to help out her little sister. So, remembering the words her second grade teacher had used, Dianne did her best to explain how it worked. "When the bottom number is bigger than the top number," Dianne said, "you have to go next door and borrow ten from your neighbor, number 5. Ten plus six is sixteen, and now you can subtract seven and get nine. But since you borrowed ten from the five, you are left with four. Four minus one is three, so your answer is 39."
Kathy didn't get it. She tried real hard, but she just couldn't get it. No matter how loudly Dianne tried to explain (using the same words each time), Kathy just couldn't get it. Not that night. However, Kathy kept at it and eventually she not only learned how to subtract all kinds of numbers, but she graduated Phi Beta Kappa, with honors, in (you guessed it), math.
There are a lot of lessons in life that are difficult. Sometimes we need to look at a problem from a different direction, or hear the lesson using different words, or sometimes we need to grow a little older and have more life experience before we "get it." Some of Jesus' teachings were difficult to understand. In today's Scripture reading, Jesus' disciples say, "This lesson is hard! Who can understand it??" I encourage you to keep at it, even when you don't understand something right away--whether it be a school lesson or a life lesson. Keep at it and eventually, even if it's in the sweet by-and-by, when we get to heaven, the problem, the question, the lesson will make sense by the grace of God.