Question 54

Colin is skip-counting by 10s and adding on.

Colin is engaged in the process of skip-counting by 10s and then adding to reach a total. This strategy allows him to efficiently reach numbers that are multiples of 10, thereby enhancing his numerical understanding.

A) Decomposing 77 into 10s and 1s

This option is incorrect because decomposing 77 into 10s and 1s would involve breaking down the number into its constituent parts, such as 70 and 7. Colin's actions, as described, do not focus on decomposition but rather on a counting method.

B) Counting on from a multiple of 5 and 11

This option is also incorrect. Counting on from multiples of 5 and 11 does not align with Colin's method of counting by 10s. His approach does not involve these specific multiples, making this choice irrelevant.

C) Skip-counting by 10s and adding on

This option accurately describes Colin's activity. He is using skip-counting, which allows him to count in increments of 10, and the addition suggests that he is building upon these multiples to reach a specific value, illustrating his understanding of patterns in numbers.

D) Finding doubles greater than 55

This option is incorrect as it implies a different numerical operation. Finding doubles greater than 55 involves multiplication, specifically focusing on pairs of numbers that sum to a value greater than 55, which does not relate to Colin's method of counting.

Conclusion

Colin's method of skip-counting by 10s and adding on is the correct explanation for his actions, as it reflects a systematic approach to numerical progression. The other options do not accurately describe his counting strategy, focusing instead on unrelated mathematical processes. This distinction is crucial for understanding basic counting techniques in mathematics.