Math Vocab.
When you read a number with a decimal, what do you say when you see the decimal?
AND
Solve the following using mental math:
8.6 + 23.4 + 1.4 =
Answer: 33.4
Estimate the numbers to find the answer:
358 + 293
Hint: Round them to the nearest hundred!
Answer: 400 + 300 = 700
Subtract the decimals using the rules:
0.67 - 0.31
Answer: 0.36
What number is in the hundredths place
45.67
7
Solve the following using mental math:
27 - 9.9 =
Answer: 17.1
Estimate the numbers to find the answer:
15.01 - 4.4 =
Hint: Round the ones place.
Subtract the decimals using rules:
8.71 - 0.4 =
Answer: 8.31
What number is in the tenths place.
9.12
1
Solve the following using mental math:
13.5 + 5.7 + 36.5 =
Answer: 55.7
Estimate the numbers to find the answer:
80.01 + 2.89 =
Hint: Round to the nearest whole number.
Answer: 80 + 3 = 83
Subtract the decimals using rules:
24.07 - 5.316 =
Answer: 18.754
What number is in the thousandths place.
1,459.127
7
Solve the following using mental math:
20.45 + 12.55 =
Answer: 33
Estimate the numbers to find the answer:
1,453.6 - 648.2 =
Hint: Round to the nearest hundred.
Answer: 1,500 - 600 = 900
Subtract the decimals using rules:
51.92 - 28.003 =
Answer: 23.917
What are the steps that we need to take in order to add or subtract decimals? (List them in order)
What are:
1) Line the decimals up or stack them on top of each other.
2) Add zeros in for place holders if needed.
3) Add or Subtract starting with the number farthest to the right and working over to the left. Carry or borrow if needed.
Solve the following using mental math:
205.4 - 99.7 =
Answer: 105.7
Estimate the numbers to find the answer:
25,003 - 12,900 =
Hint: Round to the nearest thousand.
Answer: 25,000 - 13,000 = 12,000
Solve the word problem:
Talia measured two strings. The green string was 2.37 cm long. The blue string was 4 cm long. How many centimeters longer was the blue string than the green string?
Answer: 4.00 - 2.37 = 1.63
A dragon trainer has 125.75 pounds of dragon food. During the week, the dragons eat 38.6 pounds, 27.85 pounds, and 19.9 pounds.
How many pounds of dragon food remain?
125.75 - 38.60 - 27.85 - 19.90 = 39.40 pounds