[NY07]

Hi All!

My kids are having a lot of trouble subtracting across zeros... do u have any ideas/ tips i could use to help them??

Thanks

[mojo]

I saw a post last year that helped me. I will try to explain ... If it's something like 2,000 take away 198: Take one away from 2,000 and one away from 198. You get 1,999 and 197. Then subtract. No regrouping. No borrowing. it ONLY works when the number is ending in 0s. It cannot be 1,908 for example. (the 0s cannot be in the middle). It would have to be 1,900 or 1,800 ... I hope this helps. It helped some of my kids last year.

[ggluvbug]

Go to youtube and search step ladder subtraction. It is a video on what mojo is talking about. Pretty cool and way easier.

[trainteach456]

I just taught this today. I had the kids sit on the carpet with me while I acted out the regrouping with place value models. I think me modeling is easier than giving them the models, sometimes that confuses them even more. When we had to regroup and take 100 from the hundreds I knocked on the block to break it into 10 tens (100) then wrote 10 above the 0 in the tens place. When I did not use the blocks I still knocked to show breaking the 100 flats into 10 tens. Does that sound confusing. This lesson was very teacher guided, not much time for the kids to explore how to solve the problem on their own.

[likestoteach]

I found this great website that shows the kids exactly what happens...check it out!
http://nlvm.usu.edu/

Click on numbers and operations; then base 10 subtraction

Good luck!

[annie05]

After showing them with the place value blocks, I put this saying up, have them write it, say it, and then show how they subtract - always - "all from 9, last from 10"..., they always remember, even the 4th and 5th grade teachers tell me they remember! Any time we do a subtract across the zeros we always write it, say it, and do it - "all from 9, last from 10"!

[afunteacher]

Maybe try using money. It's sometimes easier to understand than base ten (although it's the same concept). We take our $10 bill and exchange it for 10 $1 bills. Then we take a $1 bill and exchange it for 10 dimes and one dime exchanged for 10 pennies.

[trinicam]

I had my students act out the process of borrowing. I wrote a 3-digit subtraction problem on the board and had three students come to the front and hold the appropriate amount of base ten blocks. (for 205 - 127; one student would hold 5 ones, another 0 ten, and another 2 hundreds). Mr. or Ms. Subtractor would come to subtract. At the ones place he would say "I need 7 ones." The ones place didn't have enough so she would have to borrow from her neighbor the tens. Since her neighbor is a zero he would have to wait while his neighbor borrowed from the hundreds. It is important to stress that the hundred has to be broken into tens before passing it to the tens place and the tens into ones.

This is difficult to explain, but it really seemed to give my students (especially the hands-on ones) a visual of what was happening.

[Love3rdGrade]

Love the website Lovestoteach! I've been playing on it for a while now. Thanks for sharing it.

[Kermit21]

I tell my kids to save one, or put a penny under the rock, so they take one away... and make it 199 (and then put a -1 above the problem so they know they will have to add it back).
Then they subtract without renaming. Then they have to add the one back when they finish sutracting. They love it. It works really well. Hope I explained it well.
200
-176 -1 Oh let's do save one

199
-176
23

D'ont forget to add the one back 24
Hope this helps.