Estimating quotients Lesson 9-2 CCSS 4.NBT.6, 4.OA.3 Literature Link: Cheetah Math by Ann Whitehead Nagda Estimating quotients Lesson 9-2 CCSS 4.NBT.6, 4.OA.3

MATH Essential Questions What strategies can be used to divide? MATH Essential Questions

MATH Essential Questions What are different meanings of division? MATH Essential Questions

MATH Essential Questions How can mental math and estimation be used to divide? MATH Essential Questions

Warm up Henry arranges his candy into 7 rows with 8 candies per row. How many candies does he have in all? If he gives 17 candies to his sister, how many candies does he have left?

Think and write How can estimating help you divide?

Today’s Lesson In this lesson, you will learn that estimating with division is like estimating with multiplication, and it makes numbers easier to work with mentally. Let’s look at the Envision Video for this lesson and take the quiz.

Estimation review When rounding to the nearest ten, the ones place is the boss and tells you to round up or down. When rounding to the nearest hundred, the tens place is the boss and tells you to round up or down. If the number in the “boss place” is 4 or lower, round down. If the number is 5 or higher, round up.

Estimation practice Round to the nearest ten. 473 246 319 298 552

Dividing using estimation Sample Problem: Sean has 326 pennies. He puts them into 4 piles. How many pennies are in each pile? Estimation would make this problem easier to solve. Round 326 to the nearest ten. What is it? It is much easier to divide 320 by 4 than 326. How many times does 4 go into 32? 0? The quotient is 80.

Practice! Estimate by rounding to the nearest ten, then divide. 254 ÷ 5 517 ÷ 2 363 ÷ 9 562 ÷ 8 477 ÷ 6

Problem 1 Harry’s Hot Dogs has 362 hot dogs. If they have to divide them into 4 containers for transportation, how many hot dogs will go into each container? Estimate, then solve.

Problem 2 Sarah is arranging 184 sodas for her party into coolers. If she has 3 coolers, about how many sodas would go into each cooler?

Problem 3 The baker makes 238 pies. She wants to divide them between 6 different stores. About how many pies will she send to each store?

Lesson Wrap Up In this lesson, you learned that estimating with division is like estimating with multiplication. In both, you use numbers that are easier to work with mentally. Reflection in Notebook: What I found helpful in today’s lesson was…. Center Activity – Toss and Talk (9-2). Homework (9-2 Practice) for one “Paw Signature” and (9-2 Reaching & Practice) if you want two “Paw Signatures.” Website for Practice: Website for Practice: http://www.math-play.com/Rounding-Numbers-Pirate-Game.html