Post on 13-Sep-2020
Put the biggestnumber in your
head and count on.
6 +2 = 8
2+6= ?Counting on from the larger number
Addition and Subtraction NS1.2 Penny Draper
Friends of ten!7+3=10 6+4=10 5+5=103+7=10 4+6=10 10+0=108+2=10 2+8=10 1+9=10
How many different ways can you make ten?
Whole Number NES1.1 Penny Draper
Jump Strategy
46 + 33 =
2.Jump by tens first.
+30
+33.Jump by ones
46 56 66 76 77 78 79
1.Start at the biggest number.
Addition and Subtraction NS1.2 Penny Draper
Split Strategy
46+33=
1. Separate the tens and ones first.
40 + 6 +30 +3 =
2. Add the tens together
40 + 30 = 70
3. Add the ones together
6+3 =9
4. Add both totals together to find your answer.
70 + 9 = 79Addition and Subtraction NS1.2 Penny Draper
Counting on andoff the decade by
tens1 2 3 4 5 6 7 8 9 1011 12 13 14 15 16 17 18 19 2021 22 23 24 25 26 27 28 29 3031 32 33 34 35 36 37 38 39 4041 42 43 44 45 46 47 48 49 5051 52 53 54 55 56 57 58 59 6061 62 63 64 65 66 67 68 69 7071 72 73 74 75 76 77 78 79 8081 82 83 84 85 86 87 88 89 9091 92 93 94 95 96 97 98 99 100
Example 1 Counting Forwards:
20, 30, 40…. (On the decade)
27, 37, 47…..(Off the decade)
Example 2 Counting Backwards:
40, 30, 20…. (On the decade)
47, 37, 27 … (Off the decade)
Whole Number NS1.1 Penny Draper
Patterns and Algebra PAS1.1
Put the biggestnumber in your head
and count back.
8 - 2 = 6
8-2 = ?Counting back from the largest number
Addition and Subtraction NS1.2 Penny Draper
How many wayscan you make
20?10 + 10 = 20 18+2 =20 13 + 7= 20
15 +5 = 20 17 + 3 = 20 14 + 6= 20
19 + 1= 20 16+4 = 20 12+8=20
Whole Number NES1.1 Penny Draper
Using doublesand near doubles
5 +7=?
Step 1: Double 5
Step 2: Add 2
Addition and Subtraction NS1.2 Penny Draper
RelatedAddition andSubtraction
15 +3 = 18
18 – 15 = 3
18 – 3 = 15
Look for the relationship between addition and
subtraction number facts. Look for the variety
of number patterns.
Addition and Subtraction NS1.2 Penny Draper
Patterns and Algebra PAS 1.1
Equal Groupsand Arrays
2 Groups of 3
or 2 Rows of 3
Multiplication and Division NS1.3 Penny Draper
Rhythmic orSkip Counting
4 groups of 2 = 8
2 4
6 8Multiplication and Division NS1.3 Penny Draper
Whole Number NS1.1
RepeatedAddition
3 groups of 2 = 6
is the same as
2 + 2 + 2 = 6
Multiplication and Division NS1.3 Penny Draper
Bridging to 10
7 + 5 = ?
+7 3
10
7 and 3 is 10 and 2 more equals
12.
Addition and Subtraction NS1.2 Penny Draper
DecompositionMethod:
3 1
2 4 5 6
- 1 3 8 5
1 0 7 1Mental Computation strategies need to be
continually reinforced and used to check
results obtained using formal algorithms.Addition and Subtraction NS2.2 and NS3.2
Equal AddendsMethod:
1 1 1
8 0 0 0
- 1 1
617 3
7 3 2 7For students who have a good understanding of
subtraction, the equal addends algorithm may be
introduced as an alternative.
Addition and Subtraction NS2.2 and NS3.2
100
00
00
Mill
ions
100
00
0H
undr
eds
of T
hous
ands
100
00
Tens
of
Thou
sand
s
10
00
Thou
sand
s
100
Hun
dred
s
10Te
ns
1O
nes
.. (
Dec
imal
Poi
nt)
.10
Tent
hs
.100
Hun
dred
ths
Place ValueExample 1: Find the Place value of 3 in the number
4732.
3 represents 30 or 3 tens.
SharingSharing – How many in each group?
Example: “If twelve marbles are shared between three students, how
many does each get?”
Answer: 4
GroupingGrouping – How many groups are there?
Example: If I have 12 marbles and each child is to get four, howmany children will get marbles? -4
-4-4
This form of division relates to repeated subtraction.The sharing and grouping process can be reversed, showing students
the direct link between multiplication and division.Multiplication and Division NS1.3
FractionsFractions are used in different ways:
1.To describe equal parts of a whole.
2.To describe equal parts of a collection of
objects.
Fractions and Decimals NS1.4
FractionsFractions are used in different ways:
1.To describe equal parts of a whole.
2.To describe equal parts of a collection of objects.
3. To denote numbers
½ is midway between 0 and 1 on the number line.
5. As operators related to division, eg, dividing a number
in half.
Fractions and Decimals NS2.4