standard_description: Interpret multiplication as scaling (resizing), by:
- Explaining why multiplying a given number by a fraction greater than 1 results in a product greater than the given number (recognizing multiplication by whole numbers greater than 1 as a familiar case); explaining why multiplying a given number by a fraction less than 1 results in a product smaller than the given number; and relating the principle of fraction equivalence a/b = (n×a)/(n×b) to the effect of multiplying a/b by 1.
- Comparing the size of a product to the size of one factor on the basis of the size of the other factor, without performing the indicated multiplication.
problem_activity: Problem 1
A dime is
$${{1\over10}}$$
of a dollar and a penny is
$${{1\over100}}$$
of a dollar.
Would you rather have 4 one-dollar bills and 1 dime, 42 dimes, or 413 pennies? Justify your answer.
Problem 2
a.   Decide whether each of these has the same value as 3.57. Explain your reasoning.
357 tenths
357 hundredths
3 ones 57 tenths
3 ones 57 hundredths
34 tenths 17 hundredths
3 ones 7 hundredths 5 tenths
b.   Find as many ways as you can to make
$$2 \frac{4}{10}$$
using ones, tenths, and hundredths. If you think you have found all the ways, explain how you know your list is complete.
Problem 3
a.   What number represents the same amount as 1 one 70 hundredths?
b.   What number represents the same amount as 40 tenths 9 hundredths?
c.   What number represents the same amount as 268 hundredths?
d.   What number represents the same amount as 2 ones 14 tenths?
e.   What number represents the same amount as 3 ones 16 tenths 25 hundredths?


aligns: no