Yay! Decimals!
What direction do you shift if you multiply by a power of ten (whole number).
Left
Multiply:
0.5 x 0.03 =
0.015
True or False:
Multiplying by 0.1 is the same as dividing by 10?
True
What direction do you shift when you multiply by a decimal?
Right
6.4 x 1,000 =
6,400
Explain a similarity between multiplying 0.2 by 10 and 0.2 by 0.1.
In each equation the product will shift by one place value.
Fill in the blanks:
3 x 0.05 = ___ x 5 x ____
3 x 5 x 0.01
567 x 45 =
25,515
0.7 x 10^2 =
70
Which of the following equal 64?
A. 6.4 x 10^1 D. 6.4 x 10^3
B. 0.64 x 10^2 E. 64 x 10
C. 64 x 10^1 F. 64 x 1
A
B
F
Solve by using the box method:
52 x 21
1,092
Write the rules for how you solve multiplication problems.
1. Get rid of the decimals and solve as whole numbers.
2. Figure out your product.
3. Count the number of place values after the decimal in your factors.
4. Add decimal in the appropriate place.
Break apart the following:
400 x 0.05 = _____ x____x_____x_____
_____ x _____
_____
4x100x5x0.01
2000x0.01
20
Estimate to nearest tenth and solve:
0.87 x 0.6
Solve for the exact answer:
0.87 x 0.6
0.9 x 0.6 = 0.54
0.87 x 0.6 = 0.522
Hannah Ann says that the product of 80 x 50 should have two zeros. Madison says the product should have three zeros. Who is correct? Explain why.
Madison is correct.
83.4 x 8.31 =
693.054
Peter buys 4 mangos for 7 days. Each mango cost $1.26. How much does spend on mango for the week?
$35.28
Place the following in order from least to greatest.
32 x 1 32 x 10^3
32 x 10^2 32 x 0.01
0.32 x 10^1 3.2 x 10^2
32 x 0.01 ; 0.32 x 10^1 ; 32 x 1 ; 3.2 x 10^2 ;
32 x 10^2 ; 32 x 10^3
Fill in the blank (use exponents when necessary):
0.72 x ___ = 720
72 x 10^3 = ____
0.72 x ___ = 7.2
0.72 x 10^3 = 720
72 x 10^3 = 72,000
0.72 x 10^1 = 7.2
Victoria buys 5 pizzas for her 10 friends. Each pizza costs $8.35. How much money does she spend on pizza?
$41.75