Use lots of visuals!!!
Use manipulatives ex: pegs, cubes, number line. For younger children, I suggest you using loose cubes rather than the cubes that click together to connect. I have seen many struggle with the fine motor component of clicking cubes together and separating them due to lack of strength and coordination. This slows down the learning process. They become focused on the motor portion of this task and lose the attention to the math problem they are trying to solve. The loose cubes allow for more flow so that the attention is on the math equation rather than the motor skill.
Use real life examples to solve problems that children can relate to first while they learn the concept, then graduate to other “abstract” examples. For instance you can begin with problems such as, you have 3 toy cars and mom buys you 3 more cars for your bday. How many cars do you have in all? Then you can provide more abstract examples such as There are 4 birds in the tree and 2 more birds come to sit in the tree, how many birds in all?
I love using white boards to complete calculations before putting it on paper. Children tend to have less hesitation to make mistakes on a white board that they can erase. Also, for children that have difficulty with writing skills, the whiteboard has less friction and allows them to flow more easily with their writing thus the attention is on solving the math equation and not focusing on the formation of numbers or holding the pencil to paper.
Teach measurements with actual items ex: paper clip vs width of a desk. Teach volume with measuring cups and liquids, solids etc. Teach money concept with actual coins and bills. The more children can experience real life examples, the more sensory the experience and therefore the greater potential for learning.
Don’t get stuck on teaching with worksheets. There are many wonderful games that can be used to teach math concepts. I like to use Pop the Pig for number recognition, counting and also writing down the numbers. I also have children pick 2 burgers and add up the numbers. Motivation facilitates learning. After playing a game like this, I like to give them one or 2 worksheet problems and relate the concept t the game we just played so that they themselves can see the direct relationship between the worksheet math and game math. ex: After pop the pig game where they pick up numbered burgers and feed the pig, I make them do a math equation and use the burgers example to help them solve.