Many older students might find these a little daunting. When presented correctly these problems are easy and fun and teach quite a bit of simple math to the younger students whether they realize they are learning it or not.
Algebra is not usually considered one of the most by your average teacher or homeschooler but it is. See for yourself:
The video above is from a longer (21 minute) video where the 5 and 6 year old ask for more of a challenge because factoring this polynomial posed no problem. They got more of a challenge a little later on. Algebra is a fun kindergarten math activity if presented correctly. It's just a puzzle. Math requires thinking skills, logic and reasoning. Here the boys develop those skills in stages doing simple mathematics in order to solve the puzzle. They learn to add and multiply while they do algebra, if we had negative coefficients they would also learn to subtract (you can see that on the password protected pages at the house of math under "Advanced Algebra". As you can see this could even be a a preschool math activity, these boys have been doing math like this since before they were in school. All it is, is counting you could build the rectangles and have them count it. Here they are progressing naturally where they get the symbols and they have to build the rectangles and count the sides. For younger students just counting a complex rectangle can be a lot of FUN. This is math enrichment at it's best. Fun and easy, builds confidence doesn't break it.
Using base ten blocks give them hands on experience. Because they have manipulatives, the playing field is leveled and age doesn't matter: if you watch the whole video you will see there are times when the younger student figures out what to do before his older brother does. The older brother has more experience counting, adding and so forth but they both get to practice their innate problem solving skills.
Keep it fun and your students will want to learn. Algebra is just generic math, and as they play here you will be amazed at the basic concepts they discover for themselves and internalize and are then able to apply to base ten mathematics as well as other problem solving activities in algebra and math in general.
This short vid links to this longer video:
Allow them to work the problems give encouragement but don't do it for them. Very soon you will see they are doing "hard problems" with ease. Math really is child's play.