Use every opportunity to have the child count. Using coins and other small items may help keep the child interested. Draw pictures of easy geometric or fun shapes on a piece of paper and have them identify how many of each shape are on the page.
Have the child read written numbers. Teach the names of numerals one through ten and what each number represents. Let them compare written numbers to groups of items and match the numbers to the appropriate group.
Teach the importance of number order. Write several whole numbers out of order in a row. Have them order the numbers correctly. Write two numbers that are one numeral apart and have the child fill in the missing number. Write one, or a series of successive numbers together, and have the student write the numbers immediately before and after.
Slowly introduce the concept of addition and subtraction. A handful of colorful candies or beads will keep any child riveted to this lesson. Let them count the total number of candies, as well as the number of each color candy. Take one away and have them re-count. Add a couple and have the child count again.
Use everyday situations to teach. While waiting at a stoplight, have the child count the number of lights on the stoplight, the number of people in the next car or the number of people on the sidewalk. In the grocery store have them count objects, let them put four cans of soup in your cart or ask them to find how many sticks of gum are in a package. The world is an endless opportunity to teach numeration to your first grader.