Bought these after considering traditional base ten blocks and found the ability to compose and decompose units to ten rods and back again, and similarly stack ten rods together to form a hundred flat (or break it down again to rods) something we wanted for teaching regrouping according to place value, both for addition/subtraction, and multiplication/division. These interlockable blocks are also great for teaching surface area and volume and fractions, decimals, and percents.

Kudos for Amazon's customer service also: our order came without the book, but an online chat with a representative resolved the issue nicely.

The activity book has many of the same activities from the ETA Cuisenaire Super Source books, but in a more condensed form with instructions for use that are more concise and easy to apply. The activity book includes blackline masters for activities, and each lesson has a description for the teacher on the left page along with standards covered and materials list, and the reproducible activity sheet to hand out to students, on the right. It also organizes activities by the grade ranges of K-2, 3-4, and 5-6, which means the set is useful for many different ages and stays useful for many years.

As to the quality of the blocks, and I was concerned after reading reviews, but my blocks are well-made, seem sturdy and precisely molded, and the individual units are a cubic centimeter. They can go together either loosely or tightly, but I recommend attaching them loosely when joining them together, to make them easier to separate again. The hundreds flats do come snapped together quite tightly to form a second perfect thousand cub, and a Lego separator or other thin, flat, rigid device may help pry them apart that first time. Thereafter, I don't attach them perfectly, but loosely, so as to avoid that problem when taking them apart.

The thousand cube that is not made of hundred flats, seems molded in one piece (there was no removable lid as one customer showed, so the manufacturing seems to have improved) and quite sturdy, and reasonably heavy though not as heavy as the cube that can be made from hundreds flats. As others have warned, these don't have rounded corners. They appear molded precisely and with very square, sharp corners, so dropping one on a bare foot would probably hurt.

Some have mentioned it being difficult to put the set back in the storage tub, but I didn't find it hard, so long as you arrange the tens rods with the same endwise orientation they arrived in, and keep the thousand block in the center of the lid. I keep my unit cubes and tens rods in the same small ziplock baggies they came in, for ease of keeping track of them and packing them away in the storage tub. My tub's lid was clear, not blue as shown. But it works.

I really like how this set teaches the teacher, quickly and clearly, by describing the activities briefly and then getting on with it.
A good textbook or curriculum that features using base ten blocks to demonstrate the physical reality of the regrouping algorithm (what some call "carrying" or "borrowing" but that is more accurately called "composing and decomposing higher and lower orders of value" by Liping Ma) in both multiplication/division, and in addition/subtraction, will also pair nicely with these.

These are fantastic! I let my son play with them for about an hour when we first got them just so he could get familiarized with them and he loved it. I love them because they are great quality for the price. They came in perfect condition no chips bends or dings. They interlock together ok. I wish they snapped on a little bit "sngggier" but it's not really a big deal for me they snap on and that's good enough. My only real wish is that the thousand cube was weighted just for clarification purposes. Other than that these are perfect. All the different values come individually packaged in zip lock bags tucked in a plastic tub with a lid. This makes putting them away super easy. Just keep the plastic zip lock bags to store them and they all fit back in perfectly and easily. I'm very happy with my purchase and Amazon Prime allowed me to get them in 2 days🤗🤗
What's included:
1 One Thousand Cube
10 Flat trays (the hundreds)
50 Rods (the tens)
100 small singles (the ones)

I bought these to help with the textile understanding of Common Core Math (100+) for my 2nd grader. She enjoys playing with them, but the one complaint I have is the 10 blocks are not easy to link together. Other than that, they're a good learning tool. (Her teacher said it's what they use in the classroom, too.)

We like how they interlock. There are some flaws in the plastic around the edges/sides but they don't affect use. The kids like them very much. Better than ones as school, they say, because they interlock and the units on tens and flats are clearly visibly separate (3D) whereas at school they are just delineated with lines.

The plastic does have some flaws throughout and, as one reviewer mentioned, the storage box is flimsy.

The solid thousand cube fell on my foot and actually cut the leather in my Dansko shoe ( it really hurt, too ) so, it is pretty sharp-edged at the corners. Just don't drop them on your feet! Thank goodness it is not "weighted" as one reviewer suggested.

As a former elementary teacher, I love these base 10 blocks. I am homeschooling my two sons currently ages 2.5 and almost 5 (one more month to go). My almost 5-year-old is working on a 1st grade level in math and these blocks are perfect for teaching him place value, math facts, and skip counting by tens. He can already do the math facts and skip counting, but now he can visually see what is happening. My 2.5-year-old promptly started putting the ones blocks tougher and counting. He is just grasping the the tens blocks have ten ones blocks in them. My favorite part of these blocks is that the ones stack together creating one whole.