Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Addition fun!

I bought this with the subtraction wrap up for my 7 year old twins. It is very durable and has even survived being played with by my one and three year olds. There was a bit of a learning curve because they didn't know how to hold the string tight enough to keep it from slipping to the incorrect number, but it didn't take long for them to catch on. Now we set the timer and race to see who can finish the fastest.