When teaching skip counting traditionally in Montessori students would use bead chains and then move onto the multiplication bead board.
Here is how I take those traditional Montessori ideas and show how they can be adapted and extended to work with students.
If you do not own bead chains use what you have. Here I am using the bead bars and tiles from the hundred board to introduce the square of 5. The square of 5 is shown alongside the short five bead chain.
After students have become proficient with the square of 5, the next piece of obvious equipment would be the long bead chain of 5 which makes a cube totalling 125.
An alternative are these cards below that clearly show the progression up in fives of the total number growing larger. When the child is competent ordering the numbers from 5 you can also show the child how you can count backwards by placing the highest number first. If you think the work could be overwhelming you can limit the numbers given.
As my son works well with items tailored to his interest and novelty I made these skip counting in five trains. First he worked with numbers to 50 and when I saw he was confident with those I introduced the higher numbers. Here you can see how I made it obvious the pattern between numbers ending with five and numbers ending with zero. When he practiced he did the activity just with the cards.
Counting backwards and starting at numbers aside from zero or one hundred or fifty is a great way to help students generalise the concept and not just know it by rote. You can use tiles from the hundred board to teach this concept. Pick a handful of multiples of five and have the student lay them out from the largest to smallest.
I use puzzles as a hands on way to cement these concepts.
I don't introduce the clip cards until the student is really confident with counting and ordering numbers in five.
With clip cards students can place a peg or counter on the correct answer and flip over the card to see whether they are correct.
Transferring skip counting knowledge to place value and equations is really helpful for students to see how this knowledge can apply to traditional equations. Even though it might be written different 25 + 5 it means the same as when a child counts up in 5 as it is the next five. As this involves transferring and generalising knowledge I wait for students to show some understanding that when skip counting up in five they are adding five to the previous number.
After this you can show the child how this knowledge applies to the multiplication board. As I don't own one I have repurposed my hundred board from 'Treasures from Jennifer' to teach this concept.
If you don't want to reinvent the wheel I have a freebie set with some skip counting in fives activities here.
You can get the full 44 page set here: