Through her work as a consultant, Burns has found that a handful of students in all classes lack an adequate foundation in basic math concepts and lag far behind their peers in both understanding and skills. Students who lack a foundation on which to build new learning are generally not well served even by well-planned, differentiated instruction; they require supplemental interventions to help them catch up. Burns shares nine strategies she has found essential to creating effective intervention lessons in math: (1) build scaffolding into lesson planning, (2) pace lessons carefully, (3) build in a routine of support, (4) foster student interaction, (5) make connections explicit, (6) encourage mental calculations, (7) use written calculations to track thinking, (8) provide practice, and (9) build in vocabulary instruction. (Contains 1 figure.)