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## 180 Days of Math for Fourth Grade Answers Key Day 81

**Directions Solve each problem.**

Question 1.

31 + 29 = ___

Answer:

31 +Â 29 = 60

Explanation:

OnesÂ Place Value

1 + 9 = 10

Put the 0 in Ones place

Carry the 1 to Tens place

TensÂ Place Value

1 + 3 + 2 = 6

Put the 6 in Tens place

Question 2.

Is \(\frac{7}{10}\) equal to \(\frac{7}{100}\)?

_____________________

Answer:

No. Since \(\frac{7}{10}\) is greater than the \(\frac{7}{100}\)

Explanation:

make denominator equal for \(\frac{7}{10}\) and \(\frac{7}{100}\)

\(\frac{7}{100}\) = \(\frac{7}{100}\)

\(\frac{7}{10}\) = \(\frac{7}{10}\) X \(\frac{10}{10}\) =Â \(\frac{70}{100}\)

If the denominators are the same, then the fraction with the greater numerator is the greater fraction.

Now compare \(\frac{70}{100}\)Â and \(\frac{7}{100}\). Then

\(\frac{70}{100}\) > \(\frac{7}{100}\). Since \(\frac{70}{100}\) has greater numerator.

So \(\frac{7}{10}\) is greater.

Question 3.

Divide 50 into 10 equal groups.

_____________________

Answer:

5 in each group

Explanation:

Divide 50 into 10 equal groups. So 50 Ã·Â 10 =5

Question 4.

100 Ã· 10 = ___

Answer:

= 10 R 0

= 10

100 divided by 10 equals

10 with a remainder of 0

Explanation:

Question 5.

What is the first odd number before 291?

_____________________

Answer:

289 is the first odd number before 291

Explanation:

a whole number that is not able to be divided by two into two equal whole numbers The numbers 1, 3, 5, and 7 are odd numbers.

286, 287 , 288 , 289 , 290 , 291

Question 6.

Fill in the missing number.

60, 54, ___, 42, 36

Answer:

60, 54, 48, 42, 36

Explanation:

The above pattern is multiples of 6

6 x 6 = 36

6 x 7 = 42

6 x 8 = 48

8 x 7 = 54

Question 7.

Write the length in millimeters.

______________

Answer:

450 millimeters

Explanation:

Picture showing 4.5 cm

1 cm = 100 millimeters

4.5 cm = 4.5 X 100 millimeters

4.5cm = 450 millimeters

Question 8.

2 hours = ___ minutes

Answer:

2 hours = 120 minutes

Explanation:

1 hour = 60 minutes

2 hour = 2 X 60 minutes

2 hour = 120 minutes

Question 9.

A cylinder has:

____ faces

________ vertices

____ edges

Answer:

As we know a cylinder has 2 faces,Â 0 vertices and 0 edges.

Question 10.

Write two odd numbers that total the even number 50.

_____________________

Answer:

23 and 27

Explanation:

odd number: a whole number that is not able to be divided by two into two equal whole numbers The numbers 1, 3, 5, and 7 are odd numbers.

23 + 27 = 50