p ractice p roblems for 5.2 and 5.3. m ultiply 3.47 by 2.9 steps! take away the decimals. 347 * 29....
TRANSCRIPT
PRACTICE PROBLEMS FOR 5.2 AND 5.3
MULTIPLY 3.47 BY 2.9
Steps! Take away the decimals. 347 * 29. Use the multiplication algorithm. 347 * 29 = 10063 Count the decimal places! 3.47 has 2 decimal places. 2.9 has 1 decimal place. Add the decimal places. 2 + 1 = 3. Move decimal places from the right. 10063.0 becomes 10.063
MULTIPLY 49.9 BY 7.35
Steps! Take away the decimals. 499 * 735 Use the multiplication algorithm. 499 * 735 = 366765 Count the decimal places! 49.9 has 1 decimal place. 7.35 has 2 decimal places. Add the decimal places. 1 + 2 = 3. Move decimal places from the right. 366765.0 becomes 366.765
MULTIPLY 6.251 BY 52.4466
Steps! Take away the decimals. 6251 *524466 Use the multiplication algorithm. 6251 *524466 = 3278436966 Count the decimal places! 6.251 has 3 decimal places. 52.4466 has 4 decimal places. Add the decimal places. 3 + 4 = 7. Move decimal places from the right. 3278436966.0 becomes 327.8436966
WRITE A STORY PROBLEM FOR 4.2 * 3.17
Jenny put 4.2 gallons of gas into her pink Jeep. Each gallon costs $3.17. How much did she pay for gas?
WRITE A STORY PROBLEM FOR 1.8 * 5.42
Tommy went to FoodTown and bought 1.8 pounds of chicken. Each pound of chicken costs $5.42. How much did Tommy pay for chicken?
WRITE A STORY PROBLEM FOR 16 * 2.28
Marissa has 16 pairs of shoes. Each pair of shoes weights 2.28 pounds. How much do her shoes weigh in total?
FILL IN THE BLANKS!
a. A positive number * a positive number = a ________ number.
b. A positive number * a negative number = a _________ number.
c. A negative number * a positive number = a __________ number.
d. A negative number * a negative number = a _________ number.
Answersa. Positiveb. Negativec. Negatived. Positive
WHAT PROPERTY EXPLAINS WHY -4 * 6 = 6 * -4
The commutative property of multiplication.
WHAT IS -9 * 7
Answer: -63 Why? 9 * 7 = 63 One of the multiples is positive and the other
is negative, therefore the solution is negative.
WHAT IS -5 * -5
Answer: 25 Why? 5*5 = 25 Both of the multiples are negative; therefore
the solution is positive.