Q1.
A dairy farm has many cows. Chippi the lizard is surprised to see 88 legs. How many cows are there in the farm? Write appropriate sentences as above to show your thinking. Number of legs of a cow: ________ Number of cows is 88 ÷ ________ Show your work using the table below. Hint: Taking out groups of 10s is easy.
Total number of cows = ______
| No. of legs | No. of cows | No. of legs remaining |
|---|---|---|
| 88 | ||
| 40 | 10 | 48 |
| ___ | ___ | ___ |
| ___ | ___ | ___ |
Answer
| No. of legs | No. of cows | No. of legs remaining |
|---|---|---|
| 88 | ||
| 40 | 10 | 48 |
| ___ | ___ | ___ |
| ___ | ___ | ___ |
The table as it is printed in the book.
Number of legs of a cow: 4. Number of cows is 88 ÷ 4.
There are 22 cows in the farm.
| No. of legs | No. of cows | No. of legs remaining |
|---|---|---|
| 88 | ||
| 40 | 10 | 48 |
| 40 | 10 | 8 |
| 8 | 2 | 0 |
| Total | 22 |
The completed table.
40 legs are used by 10 cows. 88 − 40 = 48 legs are left.
40 legs are used by 10 more cows. 48 − 40 = 8 legs are left.
8 legs are used by 2 cows. 8 − 8 = 0 legs are left.
Total cows = 10 + 10 + 2 = 22
Check: 22 × 4 = 88 ✓
40 legs are used by 10 more cows. 48 − 40 = 8 legs are left.
8 legs are used by 2 cows. 8 − 8 = 0 legs are left.
Total cows = 10 + 10 + 2 = 22
Check: 22 × 4 = 88 ✓
Why it happens: Every cow uses up 4 legs. Taking away 10 cows at a time (40 legs) is quick, and we keep going until no legs are left.