Tuesday
Tuesday: Add and subtract like fractions
Donnie leads Bennie to a quiet pond where water lilies are blooming.
"This morning 3/8 of the pond was covered with lily pads," says Donnie.
"Since then, the lilies spread across 2/8 more."
Bennie thinks. "Both fractions are eighths of the same pond."
"So we add the eighths: 3 eighths and 2 eighths make 5 eighths."
Donnie nods. "And if a duck pushed 1/8 of the pads away?"
"Then we subtract 1 eighth," Bennie says. "That leaves 4/8."
Learn it: add the numerators
3/8 + 2/8 = 5/8. We add eighths to eighths.
The denominator stays 8. It names the size of the parts.
5/8 - 1/8 = 4/8. We take away eighths from eighths.
Adding the denominators would change the size of the parts. That is a common mistake.
- Read the question.
- Tap your answer.
- Read the question.
- Tap your answer.
Learn it: when the sum is more than one
4/6 + 5/6 = 9/6.
That is 6/6 and 3/6 more. So 9/6 = 1 3/6.
- Read the question.
- Tap your answer.
- Read the question.
- Tap your answer.
Lilies cover 3/8 of the pond, then 2/8 more. How much is covered?
Donnie walks 9/10 mile. He has walked 3/10 mile so far. How far is left?| Sentence | True or false? |
|---|---|
| 3/8 + 2/8 = 5/8 | ? |
| 3/8 + 2/8 = 5/16 | ? |
| 7/10 - 4/10 = 3/10 | ? |
| 4/6 + 5/6 = 1 3/6 | ? |
Color 3 parts blue and 2 parts red.
What fraction is colored? Write the addition sentence.
Lovely adding! Tomorrow we add mixed numbers.