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2nd Second Grade Math Tips for Teaching Subtraction with Regrouping or Borrowing
Subtraction with regrouping is often a very tricky concept for beginning
mathematicians. This concept is typically taught at around the second
grade level after the majority of the children have normal two digit
subtraction without regrouping mastered. Many parents, like me, have
struggled with helping their children grasp this concept. I have
compiled some tips and tricks that have worked while teaching my
daughter how to do subtraction with regrouping.
First, make sure your child has basic subtraction mastered. At school the teacher has to move at the speed of the class as a whole, so it's possible that some kids actually need more reinforcement in basic subtraction. Break out the worksheets or practice using everyday objects. Just make sure they can visualize the act of taking away.
Once you are certain that it's simply the regrouping that is causing most of the struggle, it's time to tackle the problems. One method that I found worked well is referring to each of the columns in a problem as "houses." They may even want to draw lines or boxes around each column to keep them separate. Remind your child that they must always start working in the ones "house." If the number upstairs is smaller than the number downstairs then they must borrow from the neighbor, which adds 10 to the current number and makes the number lower from the other side. This is also a great reinforcement to place values, because the children can now see how 10 ones is equal to one 10.
For the child who needs a more visual or hands on experience to understand math, multilink cubes are a great way to introduce or reinforce this concept. Simply build as many columns of 10 as needed for the 10s column of your problem, and use single blocks for the ones column. Then you can show the child visually how borrowing works. You move the column of 10 over to the ones section, and break them down into single blocks.
And finally for the problem of deciding whether a problem requires regrouping or not I will share this poem I found on the Proteacher website.
More on top?
No need to stop!
More on the floor?
Go next door
Get one ten
That's ten ones more.
Numbers the same?
Zero's the game!
This is a fun way to help kids learn when they need to borrow, and it also puts the process in an easy to remember format as well.
Hopefully these tips will come in handy when teaching subtraction with regrouping; there is nothing more rewarding than seeing the look of accomplishment in a child's eyes when they master a difficult concept.