First off, take away and hide all distractions!
Second off, make sure that you always keep them interested. For example, you could draw animals or symbols to intrigue them. Third off, let them explain what they think signs are and why. When subtracting, use exes, they're less confusing. When adding draw the first number out and add the other to it. Allow students to count the total. Lastly and most importantly, our fingers are our best friends in math. I'm 24 and I still count on them. I have no shame!!!! Make a rhyme while you count! This allows students to actively engage. Pay attention to the way students write their numbers. It's hard for a 6 year old to stay still, make sure you reward them! You can use stickers or a treat. They love everything!