low-tech materials like soda bottles
or popsicle sticks are more familiar to
students, they’re more approachable.
Underfunded schools and classrooms can also better afford low-cost
equipment. And using easy-to-find
materials means kids can continue to
engineer at home if they get hooked by
a challenge at school.
We find that when engineering challenges employ simple materials (for
example, designing a way to make play
dough using water, salt, and flour) students often do want to continue engineering at home, with positive results.
One teacher in a bilingual school
Every Child an Engineer
shared this story:
Last year, I worked with a very chal-
lenging student population; many
of my students had been exposed to
trauma and lacked trust in adults and
one another. This was often manifested
through a lack of motivation on school
assignments and outbursts of anger and
defiance. That changed when my class
began working on the Engineering is
Elementary chemical engineering unit,
in which students design a process
to make play dough. . . . My students
became so motivated that almost half
the class brought in samples and pro-
cesses they had developed at home
to improve the processes they were
working on in class. During class, they
discussed the quality of their samples
and tried to figure out ways to combine
their ideas to come up with the best
possible sample. . . . We ended up
comparing wheat with corn flour in
our samples, as many of my Mexican
and Central American students had
access to corn flour at home rather than
wheat, which brought in a cultural
dimension. . . . Several students ended
the unit saying they wanted to become
engineers as adults.
As we introduce children to the “new”
discipline of engineering, we should
do so in ways that will attract and
engage all learners and give stu-
dents opportunities to experience
engineering and science education
meaningfully. By applying the
inclusive design principles outlined
here, we’ll ensure that every child can
1 On its website ( www.eie.org), Engineering is Elementary provides how-to
videos and other free resources to help
educators incorporate the kinds of lessons
and activities featured in the curriculum
into their classrooms.
Carlone, H. B., Haun-Frank, J., & Webb,
A. (2011). Assessing equity beyond
knowledge- and skills-based outcomes:
A comparative ethnography of two
fourth-grade reform-based science classrooms. Journal of Research in Science
Teaching, 48( 5), 459–485.
Lee, O. (2003). Equity for linguistically
and culturally diverse students in
science education: A research agenda.
Teachers College Record, 105( 3), 465–
National Academy of Engineering (2008).
Changing the conversation: Messages
for improving public understanding of
engineering. Washington, DC: National
NGSS Lead States. (2013). Next Generation
Science Standards: For states, by states.
Washington, DC: National Academies
Christine M. Cunningham
( email@example.com) is founder
and director of the Engineering is Elementary program and Melissa Higgins
( firstname.lastname@example.org) is director of curriculum development at Engineering is
Elementary at the Museum of Science,
One student wrote, “I
like the plant project.
It was fun to mess
up and try again.”
155 Primary Mathematics Teacher’s Guide 1B © 2014 Singapore Math Inc.®
16.5a Compare numbers
• Understand that numbers have order.
• Compare numbers within 100 using a number chart.
• Sign with > on it (can be flipped)
• Sign with = on it
• Picture of crocodiles with mouths open (optional)
• Large number cards with numbers within 100
Common Core State Standard
• Greater than
• Less than
• Ask students what sign, or symbol, they use to show
that two numbers or two expressions are the same.
• Tell them that they can also use symbols to sho w that
one number is greater than or less than another.
• Have students discuss why 21 is greater than 12.
( 21 has 2 tens, and 12 has only 1 ten.)
• Point out the shape of the crocodile’s mouth. This
can help students remember that the open side
of the symbols “>” and “<” is toward the larger
number, associating them with the mouth of a greedy
crocodile that eats the greater number.
• Write 21 > 20 on the board.
• Get students to explain why 90 is less than 99. (It
has fewer ones and is 9 less.)
2 tens is greater than 1 ten.
21 is greater than 12.
We write: 21 > 12
0 ones is less than 9 ones.
90 is less than 99.
We write: 90 < 99
I always take the greater amount.
This sign means
This sign means
• Write two 2-digit numbers with different tens and same
ones digit, one above the other, with the digits aligned.
• Have students sho w both numbers with base-ten
material. Ask them to explain which number is greater.
• Have students write the numbers next to each other
and insert the symbol “>” and “<”.
• Repeat the above with two numbers with the same
tens digit but different ones digits.
• Guide students to understand the following ideas:
you then compare the ones to see which number is
• Repeat with a 1-digit number and a 2-digit number.
The first digit of the 1-digit number is greater, but
it is ones. For example, 9 has no tens. 12 is greater
because it has more tens.
42 < 62
62 > 42
56 > 53
53 < 56
9 < 12
12 > 9
G1_ TG B_4thproof_U16_16May.indd 155 16/05/14 8: 12 PM
TEACHER’S GUIDE 1A
Common Core Edition
Singapore Math Inc.®
Schools across the country
are adoptiong the new
Common Core Edition of
now with wraparound
Learn more and
for each lesson
pages featured in