Chapter 3 Whole Number Multiplication and Division

  • Chapter 3

    Chapter Objectives:

    * Place value is used to multiply and divide multi-digit numbers.

    *Estimation can be used to check the reasonableness of an answer.


    Round - To give an approximate value. A number can be rounded to the nearest ten or hundred by looking at the digit to the right of the tens or hundreds place. If it is less than 5, round down. If it is 5 or more than 5, round up.

    Estimate - An estimate is a calculated guess that is close to the exact number. An estimate of the sum of 214 and 545 is 700.

    Product - The product is the answer to a multiplication problem. Ex: 924 X 40 = 36,960. The product of 924 and 40 is 36,960.

    Regroup - To regroup is to rename; One or more digits of a number may be regrouped when adding, subtracting, multiplying or dividing. Ex: 10 ones can regroup to 1 ten or 1 ten can regroup to 10 ones. 10 tens can regroup to 1 hundred or 1 hundred can regroup to 10 tens. 10 hundreds can regroup to 1 thousand or 1 thousand can regroup to 10 hundreds. 10 thousands can regroup to 1 ten thousand or 1 ten thousand can regroup to 10 thousands.

    Remainder - The remainder is the amount left over when a number cannot be divided evenly. Ex: 12 ÷ 5 = 2 groups of 5 with a remainder of 2, or 12 ÷ 5 = 2 R2