四年级数学：第四单元复习

Study Notes

2024 Grade 4 Unit 4 Math Review

Place Value: The decimal place value chart has a different place value for each position. The highest place value in the decimal part is tenths, while the lowest place value in the whole number part is ones.
Reading Decimals: Reading decimals involves identifying the place value of each digit. For example, 5.04 is read as "five and four hundredths."
Decimal Notation: Decimal notation uses a decimal point to separate the whole number part from the decimal part. For instance, 70.209 can be written as "seventy and two hundred nine thousandths."
Counting by Place Value: The place value system dictates how a number is written. Whole numbers have ones, tens, hundreds, thousands etc. Conversely, decimals have tenths, hundredths, thousandths etc.
Comparing Decimals: Decimals are written on a number line and can be compared or ordered according to proximity to zero.
Rounding Decimals: Rounding decimals is a process of approximating a decimal to a specific place value. For example, the number 4.002 can be rounded up or down to a whole number like 4.
Converting Units: Converting units of measurement (such as centimeters to meters or grams to kilograms) is a process that relates units of different sizes. For example, 38 centimeters equals 0.38 meters.
Metric Conversions: Conversion of metric units involves understanding the relationship between metric units like meters, centimeters, millimeters, grams, kilograms, and more. 168000 can be expressed as 16.8 thousand.
Problem Solving with Decimals: Applying decimal knowledge to word problems involves applying decimal computation to calculate answers.