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Mathematics Magazine for Grades 1-12  

 

Grade 2
 

 

  
Theory:

Counting Odd Numbers by Twos

You can count by twos by either:
Adding 2 to the previous number or
Counting and skipping every other number.
The numbers that you would count if you started with 0 and counted by twos would be:
0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30 and so on.
Notice that all of the counts are even numbers.

The numbers that you would count if you started with 1 and counted by twos would be:
1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31 and so on.
Notice that all of the counts are odd numbers.

Solutions from the Previous Issue:

1.        What number should we subtract from the sum of 346 and 453 to get 527?

Solution:       346 + 453 – 527 = 272  

2.        What number are 233 smaller than the sum of 236 and 421?

Solution:       235 + 421 – 233 = 424

3.        To the sum of 443 and 221 add their difference.

Solution:       The sum is: 443 + 221 = 664. The difference is: 443 – 221 = 222

664 + 222 = 886

4.        The difference of 785 and 212 is greater that the third number with 225. Find the third number.

Solution:       The difference is: 785 – 212 = 573.

The third number is: 573 – 225 = 348

Proposed Exercises:

Count by fives. Fill in the missing number.

1.       331, 326, 321, 316, _____, 306, 301, 296, _____

2.   _____, 381, _____, 391, 396, 401, 406, _____, 416

3.     Amy and Judy sold 12 show tickets altogether. Amy sold 2 more tickets than Judy. How many tickets did each girl sell?

4.    You save $3 on Monday. Each day after that you save twice as much as you saved the day before. If this pattern continues, how much would you save on Friday?

 
 
 

Read more on the written version of the publication.