Reasoning · Grade 2-2 Making Four-Digit Numbers

Problem

Deduce digits and place values from clues

A number-fit crossword on a 6x6 grid. Each run of connected blanks takes one number, a digit per cell, and the run length must equal that number's digit count. Where an across run and a down run share a cell they must agree. The middle row already shows 4, 5, 3. Place all twelve numbers.
Your answer
How to solve
Strategy Eliminate Possibilities — The pool of numbers for each run length is small and finite, so I use the fixed digits (the given 453 and each crossing) to eliminate every number that does not fit a run, narrowing each run to one choice. The grid itself is the diagram that records the crossing digits as I lock them in.
1STEP 1

Place the two-digit numbers using the given 453

Only one two-digit number starts with 3, so 34 and 27 fall out at once.

3□ → 34, other 2-digit = 27
2STEP 2

Lock the three-digit runs through the 4 and the bottom 27

The down run from the 4 meeting that 2 is 402, and the middle across run is 453.

4□2 → 402
3STEP 3

Use the 5 to fix the first four-digit number

Just one four-digit number ends in 5, so that down run is 6715.

□□□5 → 6715
4STEP 4

Finish the four-digit runs by their crossings

Crossing that 7 and a 0 fills 4070, 4630, 3069 in turn.

□□7□ → 4070, □□□0 → 4630, last → 3069
5STEP 5

Fill the last three-digit runs

The leftover three-digit numbers land as 646, 536, 326, 325.

□4□ → 646, □36 → 536, □□6 → 326, 3□5 → 325
Answer
across 326, 4070, 536, 453, 4630, 27 / down 325, 3069, 646, 402, 6715, 34
Every run length matches the digit count of the number placed (two 2-runs, six 3-runs, four 4-runs), all twelve listed numbers are used exactly once, and every crossing digit agrees (e.g. the shared 6 between 4630 and 3069, the 7 between 6715 and 4070, the 3 between 453 and 34). The given 4, 5, 3 in row 4 is preserved.
Takeaway

Start from the digits you already know - each fixed digit crosses out choices until only one number fits each slot!

  • Place the two-digit numbers using the given 453
  • Lock the three-digit runs through the 4 and the bottom 27
  • Use the 5 to fix the first four-digit number
  • Finish the four-digit runs by their crossings
  • Fill the last three-digit runs