Unit 1

Front

What is expanded notation?

Back

Expanded notation is a way of writing numbers that shows the value of each digit. For example, the number 63,501,674 can be written as 60,000,000 + 3,000,000 + 500,000 + 1,000 + 600 + 70 + 4.

Front

How do you estimate a sum by rounding to the nearest thousand?

Back

To estimate a sum by rounding to the nearest thousand, round each number to the nearest thousand and then add them together. For example, 6,199 rounds to 6,000 and 4,832 rounds to 5,000, so the estimate is 6,000 + 5,000 = 11,000.

Front

What does it mean to round a number?

Back

Rounding a number means adjusting it to the nearest specified place value, such as the nearest ten, hundred, or thousand. For example, rounding 865,348 to the nearest hundred gives 865,300.

Front

What is the rule for rounding up?

Back

When rounding a number, if the digit to the right of the place value you are rounding to is 5 or greater, you round up. For example, rounding 7,814 to the nearest thousand gives 8,000.

Front

What is the rule for rounding down?

Back

When rounding a number, if the digit to the right of the place value you are rounding to is less than 5, you round down. For example, rounding 865,348 to the nearest hundred gives 865,300.

Front

How do you find the difference between two numbers?

Back

To find the difference between two numbers, subtract the smaller number from the larger number. For example, the difference between 23,456 and 19,500 is 23,456 - 19,500.

Front

What is the estimated difference between 23,456 and 19,500 when rounded to the nearest thousand?

Back

When rounded to the nearest thousand, 23,456 becomes 23,000 and 19,500 becomes 20,000. The estimated difference is 23,000 - 20,000 = 3,000.

Front

What is the value of the digit 6 in the number 63,501,674?

Back

In the number 63,501,674, the digit 6 is in the ten million place, so its value is 60,000,000.

Front

What is the value of the digit 3 in the number 63,501,674?

Back

In the number 63,501,674, the digit 3 is in the million place, so its value is 3,000,000.

Front

What is the value of the digit 5 in the number 63,501,674?

Back

In the number 63,501,674, the digit 5 is in the hundred thousand place, so its value is 500,000.