A Grade-by-Grade Progression
of “A Story of Units”
Scott Baldridge
Common Core
August 14, 2012
Part 1 of 2 (Grades K – 2)
Plan:
Step through “A Story of Units” grade-bygrade.
Overview Chart
Pre-Kindergarten
Well-planned math program
Count to 5 with meaning
Explore the definitions of
circle, rectangles, etc.
“How many” up to 10 using
familiarity with 5
Pre-Kindergarten
Comparisons: small, big, large, tall, etc.
Fluency with meaning of numbers 1-10,
counting numbers 1-20.
Kindergarten
Same themes as Pre-K
Numbers 1-10 with “1 more,
1 less”
Comparisons: taller than,
shorter than, longer than,
heavier than—leading to…
Kindergarten
More than, less than:



7 is 2 more than 5
7 is 2 less than 9
1 more, 2 more, 3 more than
Comparing numbers leads to
number bonds:

7
3 is less than 7. 3 and 4 make 7.
Number bonds lead to
addition/subtraction
3
4
First Grade
Fluency with add/subtract facts begins
right away and continues the entire year
Main strategy for adding/subtracting
across a 10: “make 10”
Make 10
Make
First. 10
First.
How many glasses of juice are there all together?
How many glasses of juice are there all together?
9+4=
9+4=
8 + 5 = 8 + (2 + 3) = (8 + 2) + 3 = 10 + 3 = 13
This strategy begins the realization of…
First Grade
A major concept goal for first grade:
Group “10 ones” as a single unit: 1 ten
Module 3 on length provides a few weeks
to practice “making a ten” and also allows
for a wider variety of word problems
“Add within 40” module establishes 1 ten
First Grade
“Add within 100” module begins model
work with addition and subtraction of two
2-digit numbers
In between these two heavy-duty number
modules is a module on shapes
Second Grade
The first module on “numbers to 20” is the
beginning of a yearlong fluency program
on numbers and time
The second module on measurement
plays a key role in grade 2: it establishes
the meaning of the term “unit.”
Place value units are the study of the third
module. In particular, …
Second Grade
Place value units are the basis of
the algorithms
 7 ones + 6 ones = 13 ones
= 1 ten 3 ones

1 ten + 6 tens + 2 tens = 9 tens
 1
267
+ 2 6
293
Second Grade
1 apple, 2 apples, 3 apples, ...
1 ten, 2 tens, 3 tens, …
leads to
1 three, 2 threes, 3 threes, …
4 threes = 12 ones
Second Grade
Last modules end with:
Money: dollars, dimes, pennies (and
nickels and quarters)
Analog clocks (curved number line)
Simple fractions and clocks