standard_description: Compare two decimals to hundredths by reasoning about their size. Recognize that comparisons are valid only when the two decimals refer to the same whole. Record the results of comparisons with the symbols >, =, or <, and justify the conclusions, e.g., by using a visual model.
Grade 4 expectations in this domain are limited to fractions with denominators 2, 3, 4, 5, 6, 8, 10, 12, and 100.
problem_activity: Problem 1
Look at the title and image of the Newsweek article,
More Than Half of Medical Advice on 'Dr. Oz' Lacks Proof or Contradicts Best Available Science: Study
.
According to this article, a research team looked at 80 pieces of medical advice from
The Dr. Oz Show
and found no evidence to support 43 of these recommendations.
a.   Do you agree or disagree with the claim in the headline based on this information? Why or why not?
b.   Determine whether the following fractions are greater or less than
$$\frac12$$
.
$$\frac{5}{12}$$
$$\frac35$$
Problem 2
a.   Ishmael says that he knows
$$\frac{5}{12}$$
is less than
$$\frac35$$
because
$$\frac{5}{12}$$
is less than
$$\frac12 $$
and
$$\frac35$$
is more than
$$\frac12$$
, so
$$\frac{5}{12}$$
must be less than
$$\frac35$$
. Explain why Ishmael’s reasoning is correct using words or pictures.
b.   Use Ishmael’s strategy to compare the following pairs of fractions. Record your answer with
$$\lt$$
,
$$\gt$$
, or
$$=$$
.
$${{4\over10}}$$
and
$${{5\over8}}$$
$${{7\over12}}$$
and
$${{4\over9}}$$
$${{1\over3}}$$
and
$${{4\over7}}$$
Problem 3
a.   Now Joslyn is comparing
$$\frac46$$
and
$$\frac58$$
. She says that she knows
$$\frac46$$
is more than
$$\frac58$$
because
$$\frac46$$
is
$$\frac16$$
more than
$$\frac12$$
and
$$\frac58$$
is
$$\frac18$$
more than
$$\frac12$$
and
$$\frac16$$
is more than
$$\frac18$$
. Explain why Jocelyn’s reasoning is correct using words or pictures.
b.   Use any strategy to compare the following pairs of fractions. Record your answer with
$$\lt$$
,
$$\gt$$
, or
$$=$$
.
$$\frac{5}{12}$$
and
$${{4\over10}}$$
$${{3\over5}}$$
and
$${{5\over9}}$$
$${{1\over3}}$$
and
$${{3\over7}}$$


aligns: no