Chapter 15: Divide by 2-Digit Divisors

Lesson 1: Division Patterns to Estimate. Objective: To estimate quotients using basic facts and patterns.

Lesson 2: Hands On: Model Division. Objective: To model division of 2-digit divisors using base-ten blocks.

Lesson 3: Division Procedures. Objective: To write estimates and quotients of division by 2-digit divisors.

Lesson 4: Correcting Quotients. Objective: To correct quotients when the estimate is too high or too low.

Lesson 5: Problem Solving Skill: Choose the Operation. Objective: To solve problems using the skill *choose the operation*.

Lesson 6: Find the Mean. Objective: To find the mean, or average, of a set of data.

Vocabulary: estimate, quotient, divide, divisor, mean, remainder

**estimate:** to find an answer that is close to an exact answer

**mean:** the number found by dividing the sum of a set of numbers by the number of addends

**quotient:** the number, including the remainder, that results from dividing

**remainder: **the amount left over after you find a quotient

**divisor:** the number that divides in a division problem

**divide:** to separate a number of items into equal-sized groups

Rounding Help:

**Rounding Rap**

Mark the place. Look to the right. 4 or less are out of sight. 5 and up will buy one more before they too are out the door. In those empty right-hand spaces, zeros keep the proper places.

Estimating and rounding:

http://www.math.com/school/subject1/lessons/S1U1L3GL.html

Rounding Whole Numbers: http://www.basic-mathematics.com/rounding-whole-numbers.html

Our textbook website: www.harcourtschool.com

Some good practice websites:

http://www.gamequarium.com/placevalue.html

http://www.softschools.com/math/games/

www.multiplication.com

www.funbrain.com