Numeracy
One component of our math program is learning the
skills to solve grade-appropriate problems. Children are
encouraged to verbalize their math skills through "think aloud"
strategies and "Inking Their Thinking". Most importantly, we
also guide the children to consider the applications of their
learning.
Math is everywhere! Consider the math you use when
you go to the grocery store (money, volume, mass), gas station
(money, volume), as you drive to soccer practice (time, distance),
decorate a room (measurement, patterning), baking/cooking
(measurement , time). The applications are endless!
Talk about the math you see with your child. It will
help them better understand the skills they've learned
and synthesize this knowledge in new and exciting ways!
Listed below are some fun websites that compliment
the math learned in class. Have fun!
Addition/Subtraction Strategies
Here are some strategies we will be learning to help improve speed and accuracy when adding and subtracting:
One more/less than
18+1 -> "one more than 18 = 19"
20-1 -> "one less than 20 = 19"
Two more/less than (skip one)
2+12 -> "two more than 12 = 14"
16-2 -> "two less than 16 = 14"
Three more/less than (skip two)
10+3 -> "three more than 10 =13"
17-3 -> "three less than 17 = 13"
Double Facts
With the use of pictures to help us, double facts are a snap!
Middle Facts
When looking at 6+8, we can take the number between 6 and 8 (7) and double it! So, 7 doubled = 14.
4+6 = 5 doubled
5+7= 6 doubled
Related Facts
Knowing that 3+2 is the same as 2+3 cuts down the number of math facts to learn by half! We'll be using related houses to help reinforce this skill.
Ten Facts
There's no fun twist to ten facts. They just need to be practised.
0+10 1+9 2+8 3+7 4+6 5+5
now, we can calculate the related facts....
10+0 9+1 8+2 7+3 6+4
Nine Facts
With nine facts, just substitute a "10" and then subtract one from the sum/difference.
So 9+6 -> 10+6=16 then -1 = 15
9+4 -> 10+4=14 -1 =13
Regrouping
We have begun adding double-digit numbers with and without regrouping.
This is one of the most challenging concepts in the grade two curriculum.
"Regrouping" is what we remember as carrying and borrowing. We use base ten
blocks to help us solve equations. I have used the following symbols | and * to
represent tens and ones respectively. Here's an overview:
46 is the same as saying 4 tens and 6 ones.
If we were to add 46 and 39, we would be doing the following:
(T=Tens column, O=Ones column)
TO
46 | | | | * * * * * * (46)
+_39 +_| | | * * * * * * * * * (39)
TO
1) Add the ones column. 6+9= 15
15 is the same as saying 15 ones.
We must now "regroup" the 15 ones to make 1 ten and 5 ones.
* * * * * * * * * * * * * * * becomes | * * * * *
The 5 stays in the ones column and the 1 ten is sent over to the tens column.
TO
Thinking: 15 (1 is in the tens column and the 5 is in the ones column)
TO
1
46
+__39
5
2) Add the tens column. 1+4+3=8
| | | | | | | | becomes ||||||||
TO
1
46
+__39
85
3) Double- check to ensure the answer makes sense.
Mental Math
If we were to add the numbers 33+ 46, we can use several strategies
to reach the sum mentally:
Expanding
33 + 46 = ?
33 = 30 + 3 46 = 40 + 6
30 + 40 = 70
3 + 6 = 9
70 + 11 = 79
OR
Rounding
33 rounded down to the nearest ten is 30
46 rounded up to nearest ten is 50
30 + 50 = 80
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