Sure! Here's what we use in our home off the top of my head...as well as some activities we do with the items. Think of what he enjoys playing with, characters he likes to watch on shows/movies. I find if I can relate it to something they like, they always enjoy it!
manipulatives:
colored unifix cubes (Didax) - great for showing facts (example: 5+1, 3+3, 2+4 all equal 6! Use 6 black cubes snapped together on table - 6+0, then get 3 purple & 3 red snap together and lay beside the black cubes, then 2 green & 4 orange and lay beside the other two groups of blocks...etc)
baby teddy bear counters (Learning Resouces)
colored plastic poker-style chips (Target $1 bins)
small foam cubes, triangles & cylinders (Targe $1 bins around back-to-school time)
medium and large plastic colored buttons (craft store - kid's section) - great for graphing/sorting
flat-bottom marbles ($1 store)
small erasers in various shapes - fish, palm trees, flamingos ($1 store) - great for graphing/sorting
short wood sticks - great for bundling tens! (craft store)
plastic clothespins ($1 store) - use with stiff cardboard for math facts (2 + 3 = 5 example: 2 pins on one side and 3 on the other...no matter how you turn the cardboard 2+3 and 3+2 always makes 5!
mini wood clothespins (craft store) - same as above
dried beans (black, white or kidney) - we use them in a game - We each have a "mat" which is an 8x11 piece of paper that has 10 columns, 10 small circle stickers in each column to make 100 total. We roll the dice and count that many beans onto the "mat" - once we have 10 we go to the next column. First person to make 100 wins. Then we play backwards and subtract beans back to zero.
paper number line (looks like a long gameboard 1-25) with teddy bear counter (4+2=6 - start bear on 4 then count two spaces and she lands on 6) this really helped my daughter when adding - beginning with the big number and counting on and subtracting starting on big number and moving bear backwards.
playing cards - we use them to play war (biggest number wins all cards), pick two numbers and add (ace is 1) using paper number line, pick several numbers and make 2-digit/3-digit problems (my ds uses this for Sinagpore 2 & 3) - lots of ideas on the internet for using playing cards for math games
toys:
Lego blocks & minifgures
matchbox cars
stuffed animals/beanie babies
plastic animals
Little People
Nerf Gun with darts - ds shoots at the correct number/target on markerboard to answer facts
food:
chocolate chips
mini marshmallows
fruit snacks
raisins