Mathematics Magazine for Grades 1-12  

Grade 2

Theory:

Mentally Subtracting Two Digit Numbers

Subtract 35 from 84.

• First subtract the two tens' place digits (8 - 3 = 5)

• Notice that the bottom ones' digit is larger than the top ones' digit. Decrease the answer for the tens' place by one (5 - 1 = 4) and increase the top ones' place value by 10 (4 + 10 = 14).

• Next subtract the two ones' place values (14 - 5 = 9)

• Combine the tens' and ones' place differences to make 49.

Subtract 62 from 94.

• First subtract the two tens' place digits (9 - 6 = 3)

• Next subtract the two ones' place digits (4 - 2 = 2)

• Combine the tens' and ones' place differences to give the answer of 32

Solutions from the Previous Issue:

Count by fives. Fill in the missing number.

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

Solution:

331, 326, 321, 316, 311, 306, 301, 296, 291

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

Solution:

376, 381, 386, 391, 396, 401, 406, 411, 416

3.        529, 524, 519, _____, _____, 504, 499, 494, _____

Solution:

529, 524, 519, 514, 509, 504, 499, 494, 489

4.        Katherine will go to the doctor in 5 days. Today is September 1. What is the date of her visit?

Solution:

5 days from now will be September 6.

5.        Grace made a cake for the Spring Party at her school. It was a chocolate cake. It had white icing. She put pink, yellow, and purple flowers on it. She used two and a half cups of sugar in the icing. She used half a cup of sugar in the cake. How many cups of sugar did she use in all?

Solution:

Grace used

cups of sugar in all.

Proposed Exercises:

1. Recover the operation: * 7 + 2 * + *5 = 81

2. Recover the operation: 17 + * 2 + 3* = 95

   Calculate:

3. (27 + 45) + 19 =

4. (91 –67) + 28 =

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