Math Games

Grade 1 - Number

Standard 1.N.10 - Practice solving subtraction sentences from 1 to 18.

Included Skills:

Describe and use mental mathematics strategies including
• counting on, counting back
• using one more, one less
• making 10
• starting from known doubles
• using addition to subtract
to determine the basic addition and related subtraction facts to 18.

(It is intended that students show their understanding of strategies using manipulatives, pictorial representations, and/or patterns when determining sums and differences.)
• Use and describe a mental mathematics strategy for determining a sum.
• Use and describe a mental mathematics strategy for determining a difference.
• Use and describe the related addition facts for a subtraction fact (fact family) (e.g., 6 – 4 = 2 has two related addition facts: 4 + 2 = 6, 2 + 4 = 6).
• Use and describe related subtraction facts for an addition fact (fact family) (e.g., 2 + 3 = 5 has two related subtraction facts: 5 – 3 = 2, 5 – 2 = 3).