Return to Website

 

Post a message or simply read what others have written and answered. Rachel, a RightStart™ Math user and one of our customer care people, will be monitoring this forum. She will respond to your questions as needed.

Have a great day and remember to play a math card game! 

 

Welcome
Start a New Topic 
Author
Comment
Lesson 21: Mental Addition (Level C)

I have read thru the dialog numerous times and I cannot visualize what my student is supposed to do. While I am sure that it is really quite simple, we are lost. Would someone please explain how the abacus is used? I did try searching for a video of Dutch children using this technique but found nothing as of yet.

Thanks so much!

Re: Lesson 21: Mental Addition (Level C)

Hi, Carin.

Thank you for your post! This is an approach that works very well in helping the student learn to break down problems to more easily do mental math.

The equation presented in the Lessons Manual is 76 + 39. Instead of worrying about adding all those numbers at the same time, we are going to break down that problem to be 76 + 30 first. The student will add the 76 on the second side of the abacus and then add 30. Once that has been calculated (106), then the student will add on the '9'. At this point, your child (either mentally or on the abacus) is to add 9 to 106 to get the answer of 115.

So basically, this lesson is teaching your child to split up the equation into two steps. Let's do another one. The next one on the list is 27 + 37. The first step is to add 27 + 30 (we will temporarily drop the 7). Most students can readily 27 + 30 mentally, which totals 57. Then the student will add the '7' into the total: 57 + 7 which totals 64.

Adding this extra step is extremely helpful in the mental math process. By pulling out one of the numbers, the student is able to more quickly get to solutions without confusing numbers and forgetting to 'carry', etc. It is also not as overwhelming to the child and breaks the equation into bite-sized pieces.

I hope that helps! If you have any further questions, please do not hesitate to repost here or email RightStart Math directly at info@rightstartmath.com.

Have a fabulous school year!
Rachel