Saturday, March 5, 2016

Solve My Equation

Fourth graders are always excited to finally get to learn and use the standard algorithm for subtraction.  They need a solid place value foundation first so that they have an understanding of where the numbers come from and why we "borrow" a number from the next place.  Having this knowledge helps them so much more in their mathematical learning than just telling them to cross out the number and put a one at top of the other number.  In our intervention group we worked on breaking numbers apart before we ended up at this final step.  They also continue to solve problems two ways to help solidify their understanding.  
Using the standard algorithm addresses the Common Core Standard for fourth grade.  My students love to write on the board so I had them each solve a problem up here and then they had to switch and solve the problem a second way.  Solving two ways also shows me if they have the solid understanding needed to apply the standard algorithm.  

They are solving it a second way here.  If they get a different answer they need to figure out at what step something went wrong.  This is also helping them to slow down and analyze their work to see if it makes sense.