Reasoning · Grade 2-2 Multiplication Facts
Problem
TL must divide 18, 8 and 6, leaving only 1 and 2.
If TL times something gives 8, then TL must be a number that 8 can be split into evenly - that means TL divides 8 (and 18 and 6 too).
3.OA.B.6Identify SubproblemsThe shared circle must be a number that divides 8, 18 and 6 alike, which leaves very few candidates.
If the circle times something lands exactly on 8, the circle is one of the numbers 8 splits into evenly, and each such number brings its partner with it.
Asking what the circle must be multiplied by is a missing-factor question, and dividing is exactly what answers it.
1 makes the right side 108, so 2 it is, giving 9, 4, 3.
Each circle is found by asking 'what times TL gives this line number?' - a missing-factor question.
3.OA.A.4Guess And CheckThe right side checks out: 9 × 3 = 27.
The right side was the one product we had not yet used, so it is the perfect way to confirm the guess.
3.OA.C.7Guess And CheckThe bottom box is 4 × 3 = 12.
Four groups of three (or three groups of four) is twelve - a basic times-table fact.
3.OA.A.1Guess And CheckWhen one circle touches several lines, find the number that splits all of them evenly first - then the rest fall into place with your times tables!