Today we will round very large and very small numbers. round – to replace a number by another number of approximately the same value but having fewer digits: To the nearest dollar, the rounding of $27.68 yields $28. very large numbers – numbers in the millions or higher; have 7 or more digits very small numbers - numbers in the thousandths or smaller; thousandths are fractional parts of 1000 Concept

Molly has $16 in her pocket She buys: 3 $1.89 each 3 $2.19 each 3 Large French $ $1.79 each Does she have enough money?

rounding APK to replace a number by another number of approximately the same value but having fewer digits TPS

very large numbers Numbers greater than 1 million 457,923,493 10,000,000,000,000 1,000,000 APK TPS

very small numbers.5 5 tenths numbers less than 1. They are represented by numbers to the RIGHT of the decimal point. They are also called decimals thousandths APK TPS

decimal.5 5 tenths a number less than 1. It is represented by numbers to the RIGHT of the decimal point hundredths APK

When To Round When the question asks: – “Estimate how many…” – “About how many…” – Can you think of anymore?

Why is it important that we can round very large and very small numbers? IMP  What are other reasons why it is important to know how to estimate very large and very small numbers?  Estimating is a great way to eliminate wrong answer choices  When we are asked for an estimate, this will help us figure out the answer quicker!

Let’s test the poem! The rounding poem Find your number Look right next door 4 or less, just ignore 5 or more add one more!

Rounding Whole Numbers Round 474,000,000 to the closest hundred millions. 474,000,000 Find your number Look right next door Four or less, just ignore Five or more, add one more

474,000,000 Rounded to the hundred millions becomes 500,000,000 Round 474,000,000 to the closest 10 million’s 474,400,000 Just ignore – 470,000,000

What about decimal numbers The same rules (and poem) apply! Round to the closest hundredths Find your number Look right next door 4.17

Remember If you are asked to round to the nearest tenth…….your answer stops at the tenth place! Example: Round to the closest tenth would be 42.7

Special Case! Rounding a 9 Round to the closes hundredths Since there is a “9” in the hundredths place consider the tenth and hundredths together – 19 – do you leave it at 19 or move it to 20?

Round 4.95 to the closest tenth Since there is a “9” in the tenth spot consider the ones and tenths together…… should you leave it at 49 or move it to 50? 4.95 rounded to the nearest tenth is 5.0

Let’s work some problems out together! Steps 1.Find your number 2.Look right next door 3.4 or less, just ignore 4.5 or more add one more! 125,345, ,346, ,345, ,000, ,345, ,350, ,345, ,000, ,565, ,570, ,565, ,565, ,565,484 10,000, ,565, ,000,000

Let’s work some problems out together! Steps 1.Find your number 2.Look right next door 3.4 or less, just ignore 4.5 or more add one more!

Let’s review! What does Rounding mean? What are very large numbers? Numbers in the millions or billions. Numbers like 2,304,000 and 2,455,098,098 What are very small numbers? Numbers smaller than one. Numbers like and 0.4 Closure