Invite your child to skip-count up and down by tens. Provide a starting number (e.g., 80) and ask your child to skip-count up from that number. Point a finger upward as he calls out each ten. When he passes 100, close your fist as a signal to stop, and then point downward, indicating that he should change direction and begin skip-counting down. Continue, having your child change direction periodically. Also change the upper and lower limits of the skip-counting. For example, the counting might go as follows: 80, 90, 100, 110, 120, 130. (Close fist; point downward.) 120, 110, 100, 90. (Close fist; point upward.) 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220. (Close fist; point downward.) 210, 200, 190, 180. When your child begins demonstrating strong, consistent abilities, ask him to name the ending number in unit form (e.g. 18 tens) as well as in standard form (e.g 180).
Find materials in your home—such as toothpicks, straws, crayons, or pipe cleaners—that you can gather and secure with a rubber band to form bundles of ten. Invite your child to make as many bundles of ten as possible. Have her count the bundles, skip-counting by tens. Then challenge her to state the total in unit form (e.g., 20 tens) and in standard, or number, form (e.g., 200). If she has assembled enough bundles of ten, use additional rubber bands to gather them into bundles of 100. Again, ask your child to state the total value of the bundles in unit form and in standard form.
Play family board games that incorporate counting money. Focus particularly on $1, $10, and $100 bills.
Practice counting in unit form. Partner A says a number (e.g., 234), and Partner B repeats it in unit form (2 hundreds 3 tens 4 ones). Take turns with your child being Partner A and Partner B.
Play 10 More/10 Less. Partner A says a number (e.g., 30), and Partner B says the number that is 10 less (20). After every few turns, alternate between 10 more and 10 less. You can also play 100 More/100 Less. Take turns with your child being Partner A and Partner B.
Play How Many Tens? Partner A says a number (e.g., 23 ones). Partner B tells how many tens are in the number (2 tens). You can also play How Many Hundreds? or How Many Hundreds and How Many Tens? Encourage your child to give each answer in both unit form (e.g., 3 hundreds 2 tens 5 ones) and standard form (325). Again, take turns with your child being Partner A and Partner B.