Transcript Place Value
Place Value decimal style Warm-Up Use your knowledge of place value to answer the following questions. How many thousands does it take to make 10 thousand? How many tens does it take to make 100,000? How many hundreds does it take to make 1,000,000? How would you explain your answer without using the zero trick? Whole Number Review bundles of 10 tens bundles of 10 ones single ones hundreds tens ones 7 4 3 Whole Number Review 10 x 10 x 100 x hundreds tens ones 7 4 3 What are decimals? Decimals are pieces of one or pieces of one whole. Money will help you understand decimals. One dollar = 10 dimes, 100 pennies 1 dime is 1/10 of a dollar 1 penny is 1/100 of a dollar The names dime and penny tell you how many pieces the dollar has been broken into. What are decimals? A dime is 1/10 of the whole or one-tenth 0.1 A penny is 1/100 of the whole or one-hundredth 0.01 What difference do you notice in the placement of the 1 in these two numerals? 0.1 0.01 How are decimal place values named? 0.1 0.01 When the numeral moves to the left, its value becomes ten times smaller or it is divided by 10. How are decimal place values named? 0.1 – one tenth 0.01 – one hundredth 0.001 – one thousandth What do you notice about the names of the place value columns as the digit moves to the left? Decimal Place Value one tenth hundredth thousandth Reading Decimals one 3 tenth and 4 hundredth thousandth 8 6 Read the name of the numeral after the decimal as a unit then read the last place value used after the numeral. Reading Decimals one 8 and tenth hundredth 0 0 thousandth 3 Read the name of the last place value used after the numeral. Reading Decimals one 0 and tenth hundredth 6 0 thousandth 1 Read the name of the last place value used after the numeral. Understanding Decimals one 3 tenth and hundredth 0 0 ÷ 10 thousandth 0 ÷ 10 Divide a dime by ten and you get a penny. Divide a penny by 10 and you get a thousandth Understanding Decimals one 3 tenth and 0 hundredth 0 ÷ 100 thousandth 0 Decimals and Fractions 0.13 Say the name of this decimal out loud. Say it again – louder. How would you write this decimal as a fraction? 13/100 What does the name of the decimal have to do with the fraction? Apply What You Know If 8/10 = 0.8, then how would you write 3/5 as a decimal? 3/5 = 6/10 so 3/5 = 0.6 If 14/100 = 0.14, then how would you write ¼ as a decimal? ¼ = 25/100 so ¼ = 0.25 Think About This How can division help you find the decimal equivalent of fractions? Try it on these fractions: 6/20 5/25 Let’s Turn It Around How would you write these decimals as mixed numbers? 3.02 14.5 2.07 2.67 Let’s Turn It Around How would you write these decimals as mixed numbers? 3.02 = 3 2/100 14.5 = 14 5/10 2.07 = 2 7/100 2.67 = 2 67/100 Practice What You Know Open you textbook to page 9. Work with a partner on problems 831. Write your answers in your spiral under the heading: Tenths and Hundredths 1.2 page 9 (8-31)