Lesson 5
Decimal Points in Products
Let’s look at products that are decimals.
Problem 1

Find the product of each number and \(\frac{1}{100}\).
122.1
11.8
1350.1
1.704
 What happens to the decimal point of the original number when you multiply it by \(\frac{1}{100}\)? Why do you think that is? Explain your reasoning.
Problem 2
Which expression has the same value as \((0.06) \boldcdot (0.154)\)? Select all that apply.
\(6 \boldcdot \frac{1}{100} \boldcdot 154 \boldcdot \frac{1}{1,000}\)
\(6 \boldsymbol \boldcdot 154 \boldcdot \frac{1}{100,000}\)
\(6 \boldcdot (0.1) \boldcdot 154 \boldcdot (0.01)\)
\(6 \boldsymbol \boldcdot 154 \boldcdot (0.00001)\)
0.00924
Problem 3
Calculate the value of each expression by writing the decimal factors as fractions, then writing their product as a decimal. Show your reasoning.
 \((0.01)\boldcdot (0.02)\)
 \((0.3) \boldcdot (0.2)\)
 \((1.2) \boldcdot 5\)
 \((0.9) \boldcdot (1.1)\)
 \((1.5)\boldcdot 2\)
Problem 4
Write three numerical expressions that are equivalent to \((0.0004) \boldcdot (0.005)\).
Problem 5
Calculate each sum.
 \(33.1+ 1.95\)
 \(1.075 + 27.105\)
 \(0.401+9.28\)
Problem 6
Calculate each difference. Show your reasoning.
 \(13.2  1.78\)
 \(23.11  0.376\)
 \(0.9  0.245\)
Problem 7
On the grid, draw a quadrilateral that is not a rectangle that has an area of 18 square units. Show how you know the area is 18 square units.