Question

Which pair of numbers shows the second number is an estimation of the first
345;400
0.00345;0.003
275;200
0.00345;0.004

Answer 1

To determine which pair shows that the second number is an estimation of the first, we need to see which second number is a rounded or simplified version of the first number.

1. **345; 400**: Here, 400 is a rough estimate (rounding up) of 345.
2. **0.00345; 0.003**: Here, 0.003 is a rough estimate (rounding down) of 0.00345.
3. **275; 200**: Here, 200 is not a close estimate of 275.
4. **0.00345; 0.004**: Here, 0.004 is a rough estimate (rounding up) of 0.00345.

Based on this review, the two pairs where the second number is an estimation of the first are:
- **345; 400**
- **0.00345; 0.004**

Among the options, the pairs *0.00345; 0.004* show the second number is a reasonable estimation of the first as it rounds up to the nearest significant figure.