Wednesday
Wednesday: Subtract and mixed numbers
Riley has a ribbon 3/4 of a yard long for his lantern.
He cuts off 1/3 of a yard to tie a puzzle bag.
"How much ribbon is left?" he wonders.
Later, Riley and Bennie look at the trail map.
"The path to the creek is 2 1/2 miles," says Bennie. "The path to the hill is 1 1/3 miles."
"How far is it to walk both paths?" asks Riley.
Bennie smiles. "We can add the wholes and add the fractions."
Learn it: subtract with a common denominator
Rewrite 3/4 as 9/12 and 1/3 as 4/12.
Subtract the twelfths: 9/12 - 4/12 = 5/12.
Riley has 5/12 of a yard of ribbon left.
Learn it: mixed numbers
2 1/2 + 1 1/3: add the wholes, 2 + 1 = 3.
Add the fractions: 3/6 + 2/6 = 5/6.
So 2 1/2 + 1 1/3 = 3 5/6 miles.
Sometimes we need to trade. 3 1/4 - 1 1/2 is 3 1/4 - 1 2/4.
There are not enough fourths, so trade 1 whole for 4 fourths: 3 1/4 = 2 5/4.
Then 2 5/4 - 1 2/4 = 1 3/4.
- Read the question.
- Tap your answer.
- Read the question.
- Tap your answer.
- Read the question.
- Tap your answer.
- Think about how Bennie trades a whole.
- Tap the steps in order.
| Sentence | True or false? |
|---|---|
| 3/4 - 1/3 = 5/12 | ? |
| 7/8 - 1/4 = 6/4 | ? |
| 2 1/2 + 1 1/3 = 3 5/6 | ? |
| 3 1/4 - 1 1/2 = 2 3/4 | ? |
Measure a crayon or a spoon to the nearest fourth inch.
Measure a second thing to the nearest half inch.
Subtract to find how much longer one is than the other.
Nice trading! Tomorrow Chris tells a story about a trail walk.