Editor's note: This post was originally published on February 17, 2015.
I am always amazed by the number of students that don’t understand that our place value system (e.g. where the digit in a number is) is based on the number 10. It’s one of the first questions I ask when I walk into a classroom and most of the time students have no idea!
Here's why the Base 10 System is such an important concept for your children to understand: everything in our number system revolves around the number 10. And for students to understand adding, subtracting, fractions, decimals, etc., they need to understand how the number 10 is the foundation of number sense.
There are many little games and activities we can do to help our children understand this concept and become more fluent in counting and using mental math. Here are four great ones to try out:
- Skip count by 10's: Many children memorize at an early age how to count by 10's; 10, 20 30, and so on. It is from rote memory that they develop this skill but it does not mean they really understand how to count by 10's. Encourage your children to start at a different number and count by 10's. For example 4: 4, 14, 24, 34, 44, 54, 64, 74, 84, 94, 104….and so on. Have them do this backwards. Start at a number (94) and have them count back by 10's.
- Skip count by 100: Follow the activity from above but this time count by 100, but start at a different number. For example 9: 9, 109, 209, 309, 409, 509, 609, 709, 809, 909, 1,009… It is very telling to see where children struggle the most in their counting. It gives great insight into their understanding. As a challenge, have them count back by 100!
- Multiply by groups of 10: Students need to understand that our place value system increases and decreases by groups of 10. So we want to build their mental math capability by multiplying and dividing by 10. Provide a starting number and have your children multiply the number by 10, 100, 1,000. For example 45: 450; 4,500; 45,000. Encourage them to see patterns in these numbers.
- Divide by groups of 10: Follow the activity from above but now divide by groups of 10. For example: 80,000: 8,000, 800, 80, 8. This activity sets up the understanding of decimals, which begins in 4th grade. As a challenge, begin to incorporate these activities with decimals. For example 9.02: 9.02 x 10 = 90.2; 902 X 10 = 9,020….
If students have a strong sense of place value and the base 10 system, they will be able to apply it to all types of areas as they get older and move into middle school – decimals, percents, fractions, scientific notations, etc. These activities won't just help your children develop a deeper understanding of the Base 10 System, but will help them become flexible with numbers in general.
If you'd like to learn more about ten frames yourself, don't miss my post, Learn Your Child's Math With This Ten Frame Printable.
What games or activities do you enjoy practicing with your child to build on their number sense? Share them with us on the Scholastic Parents Facebook page!