Counting is one of the most fundamental of mathematical skills. Students learn to count by twos -- 2, 4, 6, 8 and so on -- as well as by fives -- 5, 10, 15, 20 and so on. Counting by 100s and by 1,000s should also be learned. Going around the room with each student providing the next number in sequence is a fun way to teach these skills.
Teaching students to tell time is a lot easier if you have a clock where you can remove the minute hand, leaving just the hour hand. Tell students that clocks were actually made this way in the Middle Ages. When students can tell time with a one-handed clock, adding the missing minute hand should quickly improve their accuracy.
Reading a scale -- like those found on rulers, thermostats and all kinds of meters -- takes some training. After teaching this skill to students, a good test is to provide them with a ruler and a page of items to measure, both in inches and centimeters.
Many teacher supply stores sell fake money to teach students how to make change. The skill can be taught, and tested for, by asking for change for a certain bill when an imaginary item is purchased for a specific price. Make it fun; start by asking the student what imaginary item he wishes to buy. Then have the student pay for the item with a large bill and ask them how much change to expect.
Adding, subtracting, multiplying and dividing are fundamental for further development in mathematics. Start with addition and subtraction. Use blocks or other items to demonstrate addition and subtraction. For teaching multiplication and division, use a set of small objects and arrange them in a matrix. For example, 15 erasers arranged in a 3 by 5 pattern illustrates both the fact that 3 X 5 = 15 and the fact that 15/3 = 5.
The multiplication table is the biggest memory obstacle in elementary school. It is also an excellent opportunity for teaching how to memorize large blocks of information. Look for patterns like the way that in the 9s, all the products have digits that add up to 9. For example, 7 X 9 = 63 and 6 + 3 = 9. Look for fun facts like the way the equation 56 = 7 X 8 has the digits 5, 6, 7 and 8 in sequence. Make up rhymes like: "seven is cool, seven is fine, seven times seven is forty-nine."