Powers of 10
65.3 / 103=
0.0653
Estimate: 37.4 / 3.9 =
40/4 = 10
35/3.5 = 10
39/3.9 = 10
The UIUC women's gymnastics team scored a total of 35.08 points in four events for their gymnastics competition. If they scored the same number of points in each event, how many points did she score in each?
8.77 points!
Ms. Shanks completed the following problem. Correct the exponent she used.
43.62 / 104 = 0.04362
The exponent should be a 3.
75.6/12=
6.3
0.42 / 102=
0.0042
Estimate: 431 / 3.92 =
400/4 =100
Brendan filled the gas tank on his lawnmower with 5.6 gallons of gas. He mowed his and Ms. Shanks' yard 10 times on the same tank of gas. He used the same amount of gas each time. How much gas did he use each time?
0.56 gallons of gas!
Brendan says that when you divide something by 101, it stays the same because it has a one in the exponent. What is he mistaken about?
The one in the exponent place tells you that you are dividing the number by 1 ten, meaning that the decimal needs to jump one place to the left. The number does not stay the same.
49/14=
3.5
79 / 100 =
0.79
Estimate: 37.8/6.4 =
36/6=6
40/8=5
The chef at a restaurant bought 37 pounds of crab for $46.25. How much did she pay for each pound of crab?
$1.25
Snacky says that when she wants to divide something by a decimal, she should first multiply only the divisor by powers of ten until it becomes a whole number. What is she forgetting to do? (give example)
Snacky is forgetting to do the same thing to the dividend! Whatever you do to the divisor, you need to also do to the dividend.
39/2.6=
15
8 / 1,000 =
0.008
Estimate: 90.25 / 8.3=
90/9=10
100/10=10
Char'Dae spent $231 on concert tickets for herself and 11 friends. Each ticket cost the same amount. How much did she spend on each ticket?
$19.25
Ms. Shanks tells Ms. Posey that dividing decimals using the traditional algorithm is easy because it is exactly the same as dividing whole numbers. What final step is she forgetting to finish a decimal division problem when the dividend is a decimal?
61.25/12.5
4.9
0.000372
Estimate: 4,309/36.94 =
4,000/40=100
Which division problem does the model Ms. Shanks made represent? (Show number 8 on review)
1.62 / 3 = 0.54
Challenge question! Watch Ms. Shanks solve a decimal division problem and identify her mistake.
45.92/2.8=
16.4