Tips to Helping your Fifth Grader with Place Value and Decimals in Their Math Homework

The number system is based on place values. Place values help explain long numbers and make sense of such things as the cost of items. Each place or position of a number in the decimal system has a certain value. Each place has 10 times the value as the one to the right of it. The values are divided into groups of threes separated by commas. These groupings are called periods.

Place Values

The most important part of our value system is zero. Zero holds a place value when there is no number to put there yet there are more numbers in the value. For example, 100 has two zeros, but without them, we would be reading a value of one. One is the value of the number all the way to the right and since the values increase by ten each time the next value is ten. The value continues to increase and actually looks like this:

• Million, 100 thousand/ 10 thousand/ thousand, hundreds/tens/ones.

We will use the number two million, five hundred thousand, and sixty six as an example. The easier, place value way to write this is: 2,500,066. As you notice, this number is also easier to read using numerals than it would be written out.

Decimals

Adding to place value is decimals. Since the number system includes numbers other than just whole numbers, there needs to be a way to express those. Decimals make place value decrease and help us to express numbers as small as we can make them.

Following a decimal the place values decreases towards the right by tenths, so the values look like this: ones (followed by a decimal point), tenths, hundredths, and thousandths. So the number we would usually read as twenty five point six four five would be written as 25.645. When your child needs to write a number that has a value less then one, a zero is placed in the ones place before the decimal.

Rounding

Since decimals can go on forever, your child will learn the concept of rounding off. This is a type of estimating and depending on the number can either be rounding up or down. First, your child needs to figure out which place value they need to end the number at. If the number to the right of it is 5 or above, your child will round the number up. If the number to the right is the below a five, your child will leave the number as it is. Your child can also round off whole numbers exactly the same way. An example would be 234.7685 rounded up to (because of the five) to 234.769.

The concept of place value is one of the most important skills in math to master. Your child will continue to use this skill in and outside of school. Helping them learn it now will help them learn other math skills later.