Brain teaser on 1st graders homework

[AnaheimGirl]

Yikes

This would have me stumped too. What about the carryover? How do they do that if they are going left to right?

I am amazed at how much more the kids are doing now than when we were in school at their age. His homework last night had the beginnings of fractions on it.

There's an extra step involved. They have them add the tens (or hundreds or whatever) first, then on down to the right, then they have to add the sums. Like this:

. 59
+27
. 70
+16
. 86

It feels like an extra step, (and feels really stupid!) when doing it on paper, but that's the way I've always added double-digit numbers in my head, so to me, it makes sense. They say it's supposed to help them better differentiate the place values.

I'm also amazed at how much they do earlier in school now. My 2nd grader's class dissected a cow's eye this week! (well, parent volunteers handled the scalpels!) We didn't dissect anything until middle school!

 

[LaLa]

There's an extra step involved. They have them add the tens (or hundreds or whatever) first, then on down to the right, then they have to add the sums. Like this:

. 59
+27
. 70
+16
. 86

It feels like an extra step, (and feels really stupid!) when doing it on paper, but that's the way I've always added double-digit numbers in my head, so to me, it makes sense. They say it's supposed to help them better differentiate the place values.

I'm also amazed at how much they do earlier in school now. My 2nd grader's class dissected a cow's eye this week! (well, parent volunteers handled the scalpels!) We didn't dissect anything until middle school!

Ohhhh, I see. Ya know, that really doesn't seem that bad once ya get the hang of it, but you're right, it does seem like an extra step.

I prefer the old fashioned way.

 

[kristen821]

Ohhhh, I see. Ya know, that really doesn't seem that bad once ya get the hang of it, but you're right, it does seem like an extra step.

I prefer the old fashioned way.

It isn't to bad with double digits, but they are also adding triple digits like this. When they get to the real high numbers it will take forever.

 

[mickeyboat]

Actually that (75) is what I figured Nicole's homework out to be. On her paper it was 2 ones less than tens. (something like that) Her teacher never returned it, or it got lost. I will try to remember to ask her if she still has the book and the answer when I get in to school this week.

I understand this answer, too.

I was trying to help a little girl with her homework on this "new math" one time, and I could not for the life of my figure it out. Then she explained the concept to me, and it really does make sense. That's the way I add numbers in my head, too.

Denae

 

[Rajah]

Actually, I could see how it would be either 71 or 75, too, back to the original question. Are the kids by any chance learning Roman Numerals? (I doubt it, but that's something that hasn't been mentioned).

70 in Roman numerals is LXX. 80 is LXXX. To be between 70 and 80 and have 2 tens an 1 would be most likely LXXI (71) but could also be LXXV (75).

Just an alternate thought.

 

[kristen821]

Actually, I could see how it would be either 71 or 75, too, back to the original question. Are the kids by any chance learning Roman Numerals? (I doubt it, but that's something that hasn't been mentioned).

70 in Roman numerals is LXX. 80 is LXXX. To be between 70 and 80 and have 2 tens an 1 would be most likely LXXI (71) but could also be LXXV (75).

Just an alternate thought.

That makes sense!

 

[DizBelle]

Any word on an actual answer for this yet?

 

[kristen821]

Any word on an actual answer for this yet?

My friend never asked.