90 likes | 249 Views
Multiply and divide decimals. Warm-Up. Lars gave the cashier $20 for an item that cost $8.30. How much change should he receive? It rained 1.37 inches yesterday and 0.8 inches today. How much total rain fell over the past two days?. 413. x 52. Multiply (4.13)(5.2)
E N D
Warm-Up • Lars gave the cashier $20 for an item that cost $8.30. How much change should he receive? • It rained 1.37 inches yesterday and 0.8 inches today. How much total rain fell over the past two days?
413 x 52 Multiply (4.13)(5.2) • Ignore the decimal points • Multiply like normal • Count digits after the decimals. There are three. • Put the decimal point 3 spaces to the left. 8 2 6 2 0 6 5 0 2 1 4 7 6 . 4.13 5.2 x
Vocab Divisor The # dividing into the other # Dividend The # being divided Quotient The answer
Example 2 Find the value of 15.12 ÷ 3.6. • Move decimal in dividend so it is a whole number. Move the decimal the same amount of spaces in the divisor. 151.2 ÷ 36 • Divide and move decimal up.
Example 3 Isaiah developed 30 pictures from his digital camera. He was charged $2.70. What price did he pay per picture? • Divide. • Move decimal up and add zeros. • Isaiah paid $0.09 per picture.
Example 4 Find the value of 5 ÷ 8. • Insert zeros into the problem after the decimal point. • Divide.
Exit Problems Find the value of each expression. • 5(0.72) • 0.25(1.9) • 19.6 ÷ 7 • 7.2 ÷ 0.3
Communication Prompt What part of dividing with decimals is the most challenging for you?