Addition table to 20

About this chart

An addition chart makes two things visible that a worksheet cannot. The first is that the grid is symmetrical: 3+8 and 8+3 land on the same number, so learning one fact is really learning two. The second is the run of tens along the marked diagonal — 1+9, 2+8, 3+7 — the make-ten pairs that every later strategy leans on.

Reading a chart is not cheating. A child who looks up 7+6 four times this week and finds it themselves each time is quietly memorising it; a child who is stuck and guessing is only rehearsing the guess. The chart is the scaffold you take away once it stops being needed, and the diagonal patterns are what stay behind.

Rows and columns run from 0 to 10, so sums reach 20 — the range first and second graders spend most of their time inside, and the range the addition worksheets here default to.