options: Ratios & Proportional Relationships: students learn to recognize, describe, represent, and reason with ratios, rates, proportional relationships, and percent.

Measurement & Data: students learn to work with data and measure attributes such as time, money, length, area, and volume. They may learn to compare measurements to operations and convert between different units of measure.

Number Systems and Quantity: students learn to understand the complex number system and reason quantitatively.

Counting & Cardinality: students learn to know number names and the count sequence, count to tell the number of objects, and compare numbers.

Operations & Algebra: students learn to solve problems using algebraic thinking and operations such as addition, subtraction, multiplication, and division. They may learn to identify and explain arithmetic patterns, evaluate or manipulate numerical expressions, and reason with equations and inequalities.

Number & Operations - Fractions: students learn to understand fractions as numbers and may work with them using addition, subtraction, multiplication, and division.

Number & Operations in Base Ten: students learn to work with the base-ten system and build place value understanding.

Geometry: students learn to classify geometric figures by their properties, and understand and compare the relationships between them. Students develop and use formulas to compute lengths, areas, and volumes, and they use transformations to generate new shapes and compare existing ones. Geometry can be studied with and without coordinates.

Statistics & Probability: students learn to analyze and produce data distributions, and build understanding of univariate and bivariate data. They learn to interpret data, make statistical inferences, justify conclusions, understand rules of probability, and use probability to make decisions.

Modeling: students learn to choose and use appropriate mathematics and statistics to analyze real-world empirical situations, improve decisions, and report on their conclusions and the reasoning behind them.

Functions: students learn to define, use, and evaluate functions to model relationships between quantities.
problem_activity: Problem 1
Rudy is waiting patiently for his new hens to lay some eggs.
a.   On Monday he went to the henhouse to check their nests. He has 12 hens in the house, and each hen had laid 0 eggs. How many eggs did Rudy have in total? Write an equation to represent the situation.
b.   On Tuesday when he went to the henhouse, he discovered that each of his 12 hens had laid 1 egg! How many eggs does he have now? Write an equation to represent the situation.
Problem 2
Solve.
a.
$$4\times 1 = $$
_____
b.   _____
$$= 1\times 7$$
c.
$$5\ \times$$
_____
$$=5$$
d.
$$6\div 6 = $$
_____
e.   _____
$$=9\div1$$
Problem 3
Solve.
a.
$$2\times 0 = a$$
b.
$$b = 0\times 3$$
c.
$$7\times c = 0$$
d.
$$0\div 8 = d$$


correct_option_index: 4