Beginners: with these puzzles one number is missing from each 1 to 9 number set.
Grid
G1 G2 G3 G4 G5 G6 G7 G8 G9 G10 G11 G12 G13 G14 G15 G16
Row
 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16
Column
 C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16

Beginners: with these puzzles there are two numbers missing from each 1 to 9 number set.
Grid
G1 G2 G3 G4 G5 G6 G7 G8 G9 G10 G11 G12 G13 G14 G15 G16
Row
 R1 R2 R3 R4 R5 R6 R7 R8 R9 R10 R11 R12 R13 R14 R15 R16
Column C1 C2 C3 C4 C5 C6 C7 C8 C9 C10 C11 C12 C13 C14 C15 C16

This section is for developing number memory retention.
*start timer and see how many pages you can do in 30 minutes.

            
Memory
 B1 B2 B3 B4 B5 B6 B7 B8 B9 B10 B11 B12 B13
Page 2
Memory
 M1 M2 M3 M4 M5 M6 M7 M8 M9 M10 M11 M12 M13
Page 2
Memory
 H1 H2 H3 H4 H5 H6 H7 H8 H9 H10 H11 H12 H13
Page 2