Monday
Monday: Multiply with place value
Bruce the Bobcat tightens his headband at the first challenge stop of the week.
"Welcome back, trail friends!" he calls. "This week we multiply bigger numbers."
He points to four crates stacked beside the path.
"Each crate holds 30 pinecones. How many pinecones is that?"
Bennie the Bear sets down his basket of stones.
"Big numbers are built from tens and ones," Bennie says calmly.
"If we multiply each part, one big job turns into small jobs."
Bruce flicks his tufted ears. "Then let us start with the tens!"
Learn it: times tens, hundreds and thousands
4 × 3 = 12.
4 × 30 is 4 groups of 3 tens. That is 12 tens, or 120.
4 × 300 is 12 hundreds, or 1,200.
4 × 3,000 is 12 thousands, or 12,000.
The basic fact stays the same. Only the place changes.
- Read the question.
- Tap your answer.
Learn it: break apart to multiply
To find 4 × 12, break 12 into 10 and 2.
4 × 10 = 40 and 4 × 2 = 8.
40 + 8 = 48, so 4 × 12 = 48.
Bennie writes 4 × 23 the same way.
4 × 20 = 80 and 4 × 3 = 12.
80 + 12 = 92, so 4 × 23 = 92.
- Read the question.
- Tap your answer.
- Read the question.
- Tap your answer.
- Think about how Bennie breaks numbers apart.
- Tap the steps in order.
| Sentence | True or false? |
|---|---|
| 6 × 40 = 240 | ? |
| 3 × 700 = 2,200 | ? |
| 9 × 2,000 = 18,000 | ? |
| 5 × 12 = 60 | ? |
Slide 10 in each row to the left.
Count the tens part, then the twos part.
Add them. Do you get 4 × 12 = 48?
Strong start! Tomorrow we multiply numbers with three and four digits.