Solving Grade 4 Math Problems Pages 117, 118, 119 VBT Workbook 2, Self-assessment, Exercise 175

The value of the digit 8 in the number 985,672 is:

A. 8

B. 800

C. 8000

D. 80,000

Identify the place value of the digit 8 and then determine its value.

The digit 8 in the number 985,672 belongs to the ten-thousands place, so the value of the digit 8 in the number 985,672 is 80,000.

Choose answer D.

Which 3/5 of the circles have been highlighted?

Determine the fraction representing the portion of each circle that has been highlighted: the fraction representing the highlighted portion has the numerator as the number of colored cells and the denominator as the total number of equal cells.

Figure A has highlighted 3/5 of the circles

Figure B has highlighted 1/2 of the circles

Figure C has highlighted 3/4 of the circles

Figure D has highlighted 1 circle

Choose answer A

Perform addition: 4/5 + 4/5. Which calculation method is correct?

To add two fractions with the same denominator, add the numerators together and keep the denominator unchanged.

Circle C.

Which fraction is equivalent to 5/6?

Choose B

Choose B

Choose C

Choose D

Apply the basic property of fractions: If both the numerator and denominator of a fraction are multiplied by the same natural number other than 0, the result is a fraction equivalent to the given fraction.

Choose B

Choose B

Choose B

Part 1 - 5. Solve exercise 5 - Math exercise book for 4th grade Workbook 2 page 118

Question:

A rectangular classroom has a width of about

A. 5 decimeters

B. 50 meters

C. 5 millimeters

D. 5 meters

Based on practical knowledge to predict the width of the rectangular classroom.

To measure the width of the classroom, people usually use the meter unit.

So a rectangular classroom has a width of about 5 meters.

Choose D.

Calculate:

- To subtract two fractions with different denominators, we first find a common denominator for the two fractions, then subtract them after having a common denominator.

- To multiply two fractions, multiply the numerators together and the denominators together.

- If an expression involves both addition and division, perform the division first, then perform the addition.

A rectangular piece of land has a half perimeter of 64 meters, with the width being 3/5 of the length. Calculate the area of that piece of land.

1. Diagram: consider the width as consisting of 3 equal parts, then the length consists of 5 parts accordingly.

2. Find the total number of equal parts.

3. Find the value of 1 part by dividing the sum of two numbers by the total number of equal parts.

4. Find the length (multiply the value of one part by the number of parts representing the length).

5. Find the width (subtract the length from half of the perimeter, ...).

6. Find the area = length x width.

Note: Steps 3 and 4 can be combined into one step; you can find the width first and then find the length afterward.

According to the problem, the total number of equal parts:

3 + 5 = 8 (parts)

The length of the plot of land is:

The width of the plot of land is:

64 : 8 x 5 = 40 (m)

The width of the plot of land is:

64 - 40 = 24 (m)

The area is calculated as follows:

40 x 24 = 960 (m²)

Answer: 960 m²