[KarlInOhio]

I remember doing number line exercises like this long before common core. This problem is relatively sensible and shows how to subtract hundreds, tens and ones and allows the students to learn through finding the errors of others. There’s a lot bad about common core, but I don’t think this problem is the place to do battle. Now if this is all that is taught, or if it is used to prevent full understanding rather than being a stepping stone then fight it.

[A_perfect_lady]

I suspect they are trying to teach kids ways to subtract if they don't have paper and pencil handy and have to do it in their heads. It can be difficult to hold the image in your mind that you would have in front of you if you had paper.

Personally, if I were trying to solve 427-316 in my head, I too would first take off the 300, and say to myself "Okay, now it's 127-16." Then I'd take away the 6 and think "Okay, now it's 121-10," and from there I'd be okay. I think that's what they're trying to teach here.

[Resolute Conservative]

It is just plain stupid to teach math this way.

[Usagi_yo]

-1 *scoffs* at you for being so gullible.

[wintertime]

Do you in some way ( directly or indirectly) benifit financially from the godless and socialist-entitlement Government Education Industrial Complex ( aka: “public” schools).

(Just wondering.)