BERCSCARDS
What I might BUILD & EXPLAIN
Place value cards
58
8
8 is 2 less than 10
Thisismycard
I see ten more is 68.
Add 2 to 60 +8
60 - 2 = 58
50
20 + 38 = 58
I can also see 58 + 42 = 100 because 2
and 40 are white
Therefore 100 – 42 = 58
60
I see ten more is 68.
I see ten less is 48.
8, then 2 or
Subtract
just jump down a row.
Isee58purple(standardnotation)
Isee50+8(expandednotation)
Isee42white.(standardnotation)
Isee40+2(expandednotation)
I see ten less is 48
Go back 8 then 2 for 10
REPRESENT & COMPARE
I see the purple first.
50 + 5 + 3 = 58
IfIbuiltitwithblocksIwoulduse5tensanda5and8.Doyouwantmeto?
I counted by 5's and tens. (CC)
I matched a BUILD. (B)
I wrote expanded notation. (EN)
I wrote standard notation. (SN)
I described with different 10's and
ones. (PV)
I described with equations. (E)
I used commutative property. (CP)
I used associative property. (AP)
Add 2 to 60 +8
+28
+2
+ 40
+18
58 + 42 = 100!
58 60
100
!
0
50
40
58
I see 30 + 28 and 40 + 18
2838485868788898108
I counted by tens
I demonstrated inverse operations (IO)
I compared on a numberline. (NL)
I demonstrated a growth pattern. (P)
This list is meant to demonstrate the
variation of skills that develop through this
task. The final goal is mental fluency with 2
digit number and automatic application of
properties in strategizing.
20
58 60
The difference is 2 + 20 + 4.
I am comparing to Danny’s Card. He has more than me. He has 84.
That’s 80 + 4.
I see where my 58 would be. Do you? He has 2 + 20 + 4 more than me.
I think 58 + 26 = 84, do you agree? So that means 84 – 58 = 26.
CAN YOU SEE IT?
4
80
26
84
If you go backwards it is 84 – 4 – 20 – 2 still 26
1020304050607080
Can you see it? 58 + 26 = 84 or 84 – 26 = 58
TwoDigitNumberSenseThinking1012010-2030.Allrightsreserved.glorway@thinking101.caGeriLorway
.
I see 58 in 84. I can go 58 +2 = = 60, then add 24 so 26 is the difference between 58
and 84. Go back from 84 to 54 that’s 30 then come back to 58 so remove 4 that/s
26. I proved it. Can you?
TwoDigitNumberSenseThinking1012010-2030.Allrightsreserved.glorway@thinking101.caGeriLorway
.