Grade 1 Big Ideas: Math Numbers to 20 represent quantities that can be decomposed into 10s and 1s. Addition and subtraction with numbers to 10 can be modelled concretely, pictorially, and symbolically to develop computational fluency. Repeating elements in patterns can be identified. Objects and shapes have attributes that can be described, measured, and compared. Concrete graphs help us to compare and interpret data and show one-to-one correspondence.