ELEMENTARY MATH 1

 

Learn your doubles

 

First we want to get your doubles down, these will help you in multiplication. Adding Doubles is the same as Multiplying by 2.

 

Adding is combining items together:

3+3 = &&& + &&& = &&&&&&

 

Multiplying is read as NUMBER OF ITEMS IN EACH GROUP and NUMBER OF GROUPS

so 6X2 means TWO GROUPS OF SIX or &&&&&& + &&&&&&

In other words DOUBLE the number.

 

Double Addition Fact

Answer

Multiplication Fact

1+1

2

1X2

2+2

4

2X2

3+3

6

3X2

4+4

8

4X2

5+5

10

5X2

6+6

12

6X2

7+7

14

7X2

8+8

16

8X2

9+9

18

9X2

10+10

20

10X2

 

Match your DOUBLES and then match the Addition problem to the Multiplication problem

 

 

 

  Toggle open/close quiz question

Value: 1
Match the items.
The task is to match the lettered items with the correct numbered items. Appearing below is a list of lettered items. Following that is a list of numbered items. Each numbered item is followed by a drop-down. Select the letter in the drop down that best matches the numbered item with the lettered alternatives.
a. 20
b. 4
c. 16
d. 2
e. 1
f. 10
g. 18
h. 6
i. 14
 

 Toggle open/close quiz question

Value: 1
Match the items.
The task is to match the lettered items with the correct numbered items. Appearing below is a list of lettered items. Following that is a list of numbered items. Each numbered item is followed by a drop-down. Select the letter in the drop down that best matches the numbered item with the lettered alternatives.
a. 10X2
b. 2X2
c. 4X2
d. 9X2
e. 6X2
f. 3X2
g. 8X2
h. 1X2
i. 7X2
j. 5X2
 

 

COMMUTATIVE PROPERTY

 

Commute is a word that means TO MOVE. The Commutative property means the numbers can MOVE around and swap places with each other but the answer doesn't change:

 

For example: 2+3 = 3+2; this is an example of COMMUTATIVE ADDITION

Another example: 6X2 = 2X6; this is an example of COMMUTATIVE MULTIPLICATION

 

Test yourself using the COMMUTATIVE PROPERTY:

 

 Toggle open/close quiz question

Value: 1
Match the items.
The task is to match the lettered items with the correct numbered items. Appearing below is a list of lettered items. Following that is a list of numbered items. Each numbered item is followed by a drop-down. Select the letter in the drop down that best matches the numbered item with the lettered alternatives.
a. 2X7
b. 2X4
c. 4X3
d. 5+8
e. 2X9
f. 2X5
g. 5+6
h. 9+3
i. 4+1
j. 3+4
 

Now, you have been studying your doubles, you know that MULTIPLYING by 2 means to double, and you know that the order of the numbers for multiplication and addition can switch and still give you the same answer, so test yourself with the following quiz:

 

 Toggle open/close quiz question

Value: 1
Match the items.
The task is to match the lettered items with the correct numbered items. Appearing below is a list of lettered items. Following that is a list of numbered items. Each numbered item is followed by a drop-down. Select the letter in the drop down that best matches the numbered item with the lettered alternatives.
a. 12
b. 18
c. 6+5
d. 16
e. 6
f. 14
g. 10
 

BREAKING DOWN NUMBERS

 

Math is easier if you break down numbers into pieces that you know. Imagine your two hands with 10 fingers. We want to be able to break down a number to 5 + ?

 

In other words... if you have the number 6, what does that mean for your fingers? It means 1 WHOLE HAND (5 fingers) and 1 FINGER on the other hand: 5 + 1

What about 8? That means 1 WHOLE HAND (5 fingers) and 3 fingers on the other hand.

See you can match the fingers for each number between 6 and 9.

 

 Hyperlink to DragNDrop Activity 

Adding Numbers to 10

Adding a number to 10 is very easy. Notice that 10 has 2 digits - the 1 is in the TENS place and the 0 is in the ONES place. If you add a single digit number to 10, it is added to the 0 part of the ten. A number plus zero is just the number so it is easy:

 

10

+5

15

 

10

+3

13

 

10

+7

17

 

10

+9

19

 

10

+2

12

 

 

Now you try it:

 

 Toggle open/close quiz question

Value: 1
Match the items.
The task is to match the lettered items with the correct numbered items. Appearing below is a list of lettered items. Following that is a list of numbered items. Each numbered item is followed by a drop-down. Select the letter in the drop down that best matches the numbered item with the lettered alternatives.
a. 11
b. 17
c. 19
d. 14
e. 15
 

COMBINING TO ADD QUICKLY

In the last two exercises you learned to break down a number to a 5 + another number and to add 10 + a number. Now we will combine these two activities.

 

Add 6 + 5

Step 1: Re-write 6: 6 = 5 + 1

Step 2: Add to 5: 5 + 1 + 5

Step 3: Locate your two 5's, 5+5 = 10 so now we have: 10 + 1

Step 4: Add 10 + number: 10 + 1 = 11

 

Add 7 + 6

Step 1: Rewrite 7: 7 = 5 + 2

Step 2: Rewrite: 6: = 6 = 5 + 1

Step 3: Combine: 5 + 2 + 5 + 1

Step 4: Find your two 5's, combine to be 10: 10 + 2 + 1

Step 5: Combine the 2 and the 1: 2 + 1 = 3

Step 6: Add 10 + number = 10 + 3 = 13

 

Right now this may seem like a lot of steps, but once you get good at it, you will be able to do this in your head quickly.

 

Add 5 + 9

Step 1: Rewrite 9: 5 + 4

Step 2: Add to 5: 5 + 5 + 4

Step 3: Combine the 2 5's: 10 + 4

Step 4: Add: 14

 

You should start to VISUALIZE the non-5 number as it's sum of 5 + NUMBER and SEE IT IN YOUR HEAD.

 

Add 5 + 7

SEE 7 as 5 + 2

NOW SEE 10 + 2 = 12

 

Add 5 + 6

SEE 6 as 5 + 1

NOW SEE 10 + 1 = 11

 

Try some matching:

 

 Toggle open/close quiz question

Value: 1
Match the items.
The task is to match the lettered items with the correct numbered items. Appearing below is a list of lettered items. Following that is a list of numbered items. Each numbered item is followed by a drop-down. Select the letter in the drop down that best matches the numbered item with the lettered alternatives.
a. (5 + 1) + (5 + 3)
b. 5 + 5 + 4
c. (5 + 2 ) + (5 + 3)
d. 5 + 5 + 3
e. 5 + 5 + 1
f. 5 + 5 + 2
 

Addition Strategies

 

+ 0

Anything + 0 is itself: 6 + 0 = 6

+ 1

Anything + 1 is just the next number: 8 + 1 = 9

+ 2

Count on 2 units: 4 + 2 = 6

+ 3

Count on 3 units: 8 + 3 = 11

+ 5

Break the other number into it's 5 + number parts:

5 + 8 = 5 + 5 + 2 = 12

+ 6

Break both numbers into their 5 + number parts:

6 + 7 = (5 + 1) + (5 + 2)=

10 + 3 = 13

+ 10

Just change the 0 to the number: 10 + 4 = 14

 

9's Strategy

Adding with 9 is ALMOST like adding with 10, 9 is ONE LESS than 10 - so if you have to add with a 9, pretend it is a 10 for easy adding and then take-away 1 since it was really a 9.

 

Example: 9 + 4

THINK: 10 + 4 = 14

THINK ONE LESS: 13

 

Example: 8 + 9

THINK 8 + 10 = 18

THINK ONE LESS: 17

 

Try some:

 

 Toggle open/close quiz question

Value: 1
Match the items.
The task is to match the lettered items with the correct numbered items. Appearing below is a list of lettered items. Following that is a list of numbered items. Each numbered item is followed by a drop-down. Select the letter in the drop down that best matches the numbered item with the lettered alternatives.
a. 11
b. 13
c. 16
d. 12
e. 18
f. 1
g. 15
 

ALMOST A DOUBLE

 

Another strategy is noticing that the pair of numbers is just ONE away from being a DOUBLE:

 

Example: 5+4

This is almost 5+5 but 4 is ONE LESS than 5.

We add it like 5+5 but take one less: 10 -1 =9

 

Example: 7+6

This is almost 7+7 but 6 is ONE LESS than 7.

We add it like 7+7 but take one less: 14-1= 13

 

This strategy is a little harder but with practice, you can do it!

 

Try finding the match:

 

 Toggle open/close quiz question

Value: 1
Match the items.
The task is to match the lettered items with the correct numbered items. Appearing below is a list of lettered items. Following that is a list of numbered items. Each numbered item is followed by a drop-down. Select the letter in the drop down that best matches the numbered item with the lettered alternatives.
a. One less than 3+3
b. One less than 4+4
c. One less than 9+9
d. One less than 8 + 8
e. One less than 7 + 7
 

 

Let's try putting all these strategies together: Get a piece of paper and write the answers. Try to use as many strategies as you can.

 

9 + 3

6 + 1

8 + 2

5 + 6

10 + 3

5 + 9

1 + 4

7 + 2

5 + 7

10 + 7

7 + 9

8 +1

2 + 6

5 + 9

4 + 10

6 + 9

1 + 7

2 + 4

5 + 8

10 + 8

9 + 4

5 + 0

3 + 9

6 + 6

5 + 10

8 + 9

0 + 3

7 + 3

7 + 6

7 + 7

9 + 9

8 + 0

3 + 4

8 + 7

8 + 8

 

 

ANSWERS:

 

9 + 3 =12

6+1 = 7

8 + 2 = 10

5 + 6 = 11

10 + 3 = 13

5 + 9 = 14

1 + 4 = 5

7 + 2 = 9

5 + 7 = 12

10 + 7 = 17

7 + 9 = 16

8 +1 = 9

2 + 6 = 8

5 + 9 = 14

4 + 10 = 14

6 + 9 = 15

1 + 7 = 8

2 + 4 = 6

5 + 8 = 13

10 + 8 = 18

9 + 4 = 13

5 + 0 = 5

3 + 9 = 12

6 + 6 = 12

5 + 10 = 15

8 + 9 = 17

0 + 3 = 3

7 + 3 = 10

7 + 6 = 13

7 + 7 = 14

9 + 9 = 18

8 + 0 = 8

3 + 4 = 7

8 + 7 = 15

8 + 8 = 16

 

QUESTIONS:

 

1. Which is your favorite strategy you learned? Why?

 

2. Which strategy is the most challenging? Why?

 


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