## Math Expressions Common Core Grade 4 Unit 2 Lesson 12 Answer Key Two-Digit by Two-Digit Multiplication

**Math Expressions Grade 4 Unit 2 Lesson 12 Homework**

**Sketch an area model for each exercise. Then find the product.**

Question 1.

74 × 92 _______

Answer:

Explanation:

To solve 74 X 92 first 92= 90 + 2 ( split tens and ones)

and multiplying by 74 and by adding the products of thousands and hundreds we get

74 x 92 = 74 (90 + 2) = 74 x 90 + 74 X 2 = 6660 + 148 = 6808.

Question 2.

65 × 37 _______

Answer:

Explanation:

To solve 65 X 37 first 37= 30 + 7 ( split tens and ones)

and multiplying by 65 and by adding the products of thousands and hundreds we get

65 x 37 = 65 (30 + 7) = 65 x 30 + 65 X 7 = 1950 + 455 = 2405.

Question 3.

55 × 84 _______

Answer:

Explanation:

To solve 55 X 84 first 84= 80 + 4 (split tens and ones)

and multiplying by 55 and by adding the products of thousands and hundreds we get

55 x 84 = 55(80 + 4) = 55 x 80 + 55 X 4 = 4400 + 220 = 4620.

Question 4.

49 × 63 ________

Answer:

Explanation:

To solve 49 X 63 first 63= 60 + 3 (split tens and ones)

and multiplying by 49 and by adding the products of thousands and hundreds we get

49 x 63 = 49(60 + 3) = 49 x 60 + 49 X 3 = 2940 + 147 = 3087.

Question 5.

34 × 52 ________

Answer:

Explanation:

To solve 34 X 52 first 52 = 50 + 2 (split tens and ones)

and multiplying by 34 and by adding the products of thousands and tens we get

34 x 52 = 34(50 + 2) = 34 x 50 + 34 X 2 = 1700 + 68 = 1768.

Question 6.

24 × 91 _______

Answer:

Explanation:

To solve 24 X 91 first 91 = 90 + 1 (split tens and ones)

and multiplying by 24 and by adding the products of thousands and tens we get

24 x 91 = 24(90 + 1) = 24 x 90 + 24 X 1 = 2160 + 24 = 2184.

Question 7.

Write a word problem for one exercise above.

Answer:

Word problem for 34 X 52, Laurie have 34 apples and each apple costs $52,

How much does the 34 apples cost,

It costs $1768,

Explanation:

Wrote word problem for one exercise above as word problem

for 34 X 52, Laurie have 34 apples and each apple costs $52,

How much does the 34 apples cost is?

To solve 34 X 52 first 52 = 50 + 2 (split tens and ones)

and multiplying by 34 and by adding the products of thousands and tens we get

34 x 52 = 34(50 + 2) = 34 x 50 + 34 X 2 = 1700 + 68 = 1768.

therefore apples cost $1768.

**Math Expressions Grade 4 Unit 2 Lesson 12 Remembering**

**What is 851,632 rounded to the nearest:**

Question 1.

hundred? __________

Answer:

851,600,

Explanation:

Given 851,632 rounded to the nearest hundred is,

we have 6 at hundred place so we round it as

851,600.

Question 2.

thousand? _________

Answer:

852,000,

Explanation:

Given 851,632 rounded to the nearest hundred is,

we have 1 at thousand place and 6 at hundred place so we round it as

852,000.

Question 3.

ten thousand? __________

Answer:

850,000,

Explanation:

Given 851,632 rounded to the nearest ten thousand is,

we have 5 at ten thousand place and 1 at thousand place

so we round it as 850,000.

Question 4.

hundred thousand? ___________

Answer:

900,000,

Explanation:

Given 851,632 rounded to the nearest hundred thousand is,

we have 8 at hundred thousand place and 5 plus at ten thousand place

so we round it to nearest hundred thousand is as 900,000.

**Compare using >, <,or =.**

Question 5.

58,320 58,320

Answer:

58,320 = 58,320,

Explanation:

As given to compare we have both sides same 58,320

so we use equal to as 58,320 = 58,320

Question 6.

642,810 64,281

Answer:

642,810 > 64,281,

Explanation:

Given to compare 642,810 and 64,281 as

642810 is greater than 64,281 we write as

642,810 > 64,281.

Question 7.

427,900 428,000

Answer:

427,900 < 428,000,

Explanation:

Given to compare 427,900 and 428,000 as

427900 is less than 428,000 we write as

427,900 < 428,000.

Question 8.

71,253 409,135

Answer:

71,253 < 409,135,

Explanation:

Given to compare 71,253 and 409,135 as

71,253 is less than 409,135 we write as

71,253 < 409,135.

**Draw a rectangle model. Solve using any method that relates to the model.**

Question 9.

6 × 358 = _________

Answer:

Explanation:

To solve 6 X 358 first 358= 300 + 50 + 8 ( split hundreds, tens and ones)

and multiplying by 6 and by adding the products of hundreds, tens and ones we get

6 x 358 = 6 (300 + 50 + 8) = 6 x 300 + 6 X 50 + 6 X 8 = 1800 + 300 + 48 = 2148.

Question 10.

4 × 692 = _________

Answer:

Explanation:

To solve 4 X 692 first 692= 600 + 90 + 2 ( split hundreds, tens and ones)

and multiplying by 4 and by adding the products of hundreds, tens and ones we get

4 x 692 = 4 (600 + 90 + 2) = 4 x 600 + 4 X 90 + 4 X 2 = 2400 + 360 + 8 = 2768.

**Tell what additional information is needed to solve the problem.**

Question 11.

Rosalina knitted 8 scarves for gifts. She used 38 feet of yarn for each scarf.

How much did Rosalina spend on the yarn?

Answer:

The cost of each foot of yarn,

Explanation:

Given Rosalina knitted 8 scarves for gifts. She used 38 feet of yarn for each scarf.

To know how much did Rosalina spend on the yarn we need to know the cost of

each foot of yarn.

Question 12.

**Stretch Your Thinking** How many smaller rectangles are there in an

area model that represents 27 × 83? Why? What are their dimensions?

Answer:

There are 4 smaller rectangles in the area model,

The dimensions of the smaller rectangles are

20 × 80, 20 × 3, 7 × 80 and 7 × 3,

Explanation:

There are 4 smaller rectangles in the area model

because each place value of 27 is multiplied by

each place value of 83. The dimensions of the

smaller rectangles are 20 × 80, 20 × 3, 7 × 80

and 7 × 3 respectively.