Depending on the level of your students there are 2 different rulers to choose from each with different size hearts. I have also included colored rulers and black and white rulers. Last year I used the colored ones, but I think this year I will let them color the black and white version then they can take them home and measure until their hearts content - pun intended!
Students choose a card and record how many hearts they estimate the shape to be then they measure and record the actual measurement. There is an I can.. card included to help students work independently.
I've left it at school, but I'll take pictures next week of my students using it and post them here :)
This activity is available at my TPT store but I'll send a free copy to the first 2 followers who leave a comment on this post. Don't forget your email!