# Math Corner

Math Corner

We have been learning how to tell time using both analog and digital clocks. Please practice telling time with the analog "clock" your child made at school and brought home. We are focusing only on full and half hours at this point. Try setting the clock for a time and asking your child, "What time is it?" For full hours, they should be saying the number and o'clock (i.e., four o'clock). For half hours, ask them to say both the number form (i.e., four-thirty) and the "half past" form (i.e., half-past four).

For digital time, you can simply write a few different times on a piece of paper and ask your child to tell you the time, using the same forms as for analog time. On the reverse, you can have the child show you how to write various times that you dictate. Remember to stick with full and half hours for now. Learning to tell time can be very challenging for children, as 60 units = 1 whole, whereas in other math topics they learn a system based on 10 (i.e., in counting money, we learned that 100 pennies equals 1 dollar).

Here is a link to online activities where they can practice these skills with you: http://www.aaamath.com/k8_mea-time-1h.htm for full hours, and http://www.aaamath.com/k8_mea-time-30m.htm for half hours. Your child likely will not be able to type in the word forms of the times yet, but by helping them with that part, you will expose them to something they will be learning later on.

Please keep practicing counting money with your child. You can use the "bank" of pennies, nickels, dimes and quarters that we created for the Money unit. Have students show different ways to make \$1.00. For example, you can tell them they can use only pennies and quarters, or only dimes and nickels. As they get better and better, you can limit the options more. For example, tell them they can use no more than five dimes and five nickels but as many pennies and quarters as they want.

Another fun way to practice counting money is to play "store," using various items from around the house. You can mix it up, one day making it a "grocery store" using pantry items, another day a "toy store" using their toys. Price the items in varying amounts up to \$1.00. Have your child pay you for an item by using the change from their "bank."

Below, I have included some background on our number system copied from an article I found online at http://www.googobits.com/articles/2151-the-origins-and-history-of-the-number-system.html. I thought parents might find it interesting.

### The Basis of Our Number System

The number system that we use today is a place value decimal system. What that means is that not only the number, but the placement of the number is important. Take a look at the number 536. This incorporates three numerals: 5, 3 and 6. Because we use a place value system, we know that the 5 does not stand just for 5, it means 500. The 3 stands for 30, and the 6, being in the ones place, is just 6. Rather than writing 500 + 30 + 6, our system allows us to write it simply as 536.

Our system is also decimal, because it is based upon increments of 10. We have 10 numerals in our system: 1, 2, 3, 4, 5, 6, 7, 8, 9 and 0. We count 1 through 9, then move to the next level with 10. Then we go up in the ones place through 9 before moving to the next 10s place (20). Each place value in the system is ten times the value of the one before it. (Ones, then tens, then hundreds, thousands and so on).

The vital element in making this system work is the development of the concept of zero. Aside from the Maya of Central America, the only group to develop the concept of zero was the Hindu peoples of India.